CPT International 04/2016

cptinternational

The leading technical journal for the global foundry industry – Das führende Fachmagazin für die weltweite Gießerei-Industrie

www.giesserei-verlag.de

December

2016

CASTING

PLANT AND TECHNOLOGY

INTERNATIONAL

4

Robust processes with

casting process simulation


www.bdguss.de

Call for Papers

5 th International

Cupola Conference

CCS / Saarbrücken

June, 22 – 23, 2017

Foto: Küttner GmbH & Co. KG, Essen

The deadline for submitting your abstract is

set for December, 15 th , 2016

To submit a paper, please provide a maximum

300-word abstract along with the title of the paper,

the speaker’s name and company / institute

For further information please contact:

Bundesverband der Deutschen

Gießerei-Industrie (BDG)

Simone Bednareck

Hansaallee 203, 40549 Düsseldorf / Germany

Phone: +49 (0) 211/6871-338

Fax: +49 (0) 211/6871-40-338

E-Mail: simone.bednareck@bdguss.de

Contributions are invited

in the following areas:

> Raw materials

> Metallurgy and melting process

> Plant engineering

> Control of process gases and

detection

> Energy efficiency

> Emissions, environmental issues

> Refractory materials

> Holding furnaces

> Modelling of processes


EDITORIAL K

Light metal casting is enjoying

a worldwide boom

One year comes to a close, and another starts! One cannot really expect political

stability on the global stage in 2017 in view of the unexpected election of

Donald Trump as the next US President and a European Union weakened by

Brexit. But this need not affect development of the world’s foundry sector –

after all, Trump has promised to make the US economy strong again and to

revive weak industries. Whether and when these promises will be kept remains

to be seen. The announced US economic program, however, can only be a good

thing for the world’s second-strongest foundry industry. Though a good position

in the ranking of casting producers may be of little significance in the real

world. Our author Douglas Trinowski has compared mold and core production

by US casters with that of their colleagues in the EU and brings the statistics

and rankings to life on P. 37.

When examining the last two surveys by Modern Casting on global casting

production (in 2013 and 2014) one common feature can immediately be seen:

the quantity of aluminum castings produced is rising considerably – not that

this is a great surprise given the developments towards light construction in

the automotive and other sectors.

Aluminum and other light metals also determine much of this issue of

CASTING, whether in the form of an interview with the General Manager of

the well-known die-casting machine producer Idra Riccardo Ferrario (from

P. 6), an article on the innovative HZD zinc-casting foundry (which, thanks

to its research, has created new materials and made interesting advances in

functional integration, P. 20), or a report on the Swiss die-caster DGS Druckguss

and its growth strategy for automotive structural castings (from P. 42).

Then, among other things, there is an excellent article on the high-strength

non-ferrous material Silafont-38 (P. 10) and a comprehensive specialist article

on tungsten composite materials as mold materials for die casting, written by

the Austrian Foundry Institute (ÖGI, from P. 24).

One has already started celebrating Christmas in many parts of the world. I

wish you a happy festive season in the names of all in the CASTING Editorial

Office! Of more importance here, however, is the New Year’s festival that affects

all of us – have a good new year and why not read CASTING again during the

holiday period?

Have a good read!

Robert Piterek

e-mail: robert.piterek@bdguss.de

Casting Plant & Technology 4 / 2016 3


K FEATURES

INTERVIEW

Ferrario, Riccardo

Idra is leader again 6

MATERIALS

Röders, Andreas; Röders, Gerd; Wiesner, Stuart

Practical application of high-strengh alloy Silafont-38 10

MOLDING MATERIAL

Dahlmann, Martin; Umla-Latz, Sabine; Wolff, Joachim

High performance molding material for most accurate castings 14

MELTING SHOP

Dahmen, Michael

Smart energy-efficient water recooling system is successfully employed

in induction melting plants 16

PRESSURE DIE CASTING

Piterek, Robert

The courage to carry out research 20

Cover-Photo:

MAGMA Gießereitechnologie GmbH

Kackertstr. 11

52072 Aachen

Tel.: +49 241 88901 0

Fax: +49 241 88901 60

info@magmasoft.de

www.magmasoft.de

Read our Article “Optimization of a brake caliper”

with MAGMA-casting process simulation on page 34 !

Hofer, Peter; Gössl Wolfgang; Tucan, Klaus Peter; Gschwandtner, Reinhold;

Schindelbacher, Gerhard; Schumacher, Peter

Tungsten-based composites as a die material in high-pressure die-casting 24

AUTOMATION

Vollrath, Klaus

The Olsberg foundry modernizes production of castings 30

20

30

The pressure die-casting foundry Havelländische Zink-Druckguss

GmbH & Co. KG is repositioning itself with innovative

research, automation and digitalization (Photo: BDG/Piterek)

The Olsberg foundry invested 11 million euros in new state-of-the-art

plants for the production of iron castings. Heart of the investment is

a powerful molding line which can meet high demands (Photo: HWS)


CASTING

4 | 2016

PLANT AND TECHNOLOGY

INTERNATIONAL

SIMULATION

Wang, Houming; Wu, Shiguang

Optimization of a brake caliper 34

MARKETS

Trinowski, Douglas

Comparing moding and core making trends in the U. S. and

EU casting industries 37

COMPANY

Vollrath, Klaus

Aluminium structural castings: greater capacity for Europe‘s

premium cars 42

K COLUMNS

Editorial 3

News in brief 45

Brochures 48

Advertisers´ index/Fairs and congresses 50

Preview/Imprint 51

42

DGS Druckguss Systeme AG, based in St. Gallen in Switzerland, is delivering large-format structural components for the hybrid

body of Mercedes’ new C-Class. The next step is to build up production and logistical structures that meet the customer’s needs

regarding development competence, component quality, production capacities and cost structures (Photo: Daimler AG)


K INTERVIEW

Idra is leader again

In the world of foundry, Idra stands for die casting; founded in 1946 by the Pasotti family, the

company from Brescia has built its success on innovation and technological development becoming

a point of reference since the 1960s, when the legendary “S” series represented the top

for reliability, solidity and ease of use. At Travagliato establishment, near Brescia, an interview

with CEO Eng. Riccardo Ferrario took place, a man of solid expertise in corporate turnarounds,

with thirty years of experience in aluminium foundry

Mr. Farrario, you have strongly rebuilt

Idra. What is your summary today?

When at the end of 2008 I was contacted

to relaunch the company it seemed

impossible to me that Idra was in difficulty,

without orders and with negative

perspectives; in fact, conditions

of a potential revival could be seen.

The majority of the company’s capital

was acquired during the year by

LK Machinery, an industrial giant listed

on Hong Kong Stock Exchange and

market leader in China for light alloys

foundry, injection machines for

plastic components and machining

centers. LK held 70 % share capital,

while remaining 30 % was controlled

by Intesa Sanpaolo.The company had

moved from the historic seat site to the

new Triumplina to the new plant in

Travagliato, just perfect for the production

of small, medium and large presses.

The brand was still strong, known

throughout the world and its technology

was even more valid.

Riccardo Ferrario, General Manager of the Idra Group (Photos: Idra)

But a very deep structural change was

going on, to be evaluated very carefully,

taking into account the characteristics

of the control shareholder...

In fact I spent a couple of months between

account analysis and meetings

with shareholders to understand their

intentions and I decided to accept the

challenge. The key moment was meeting

Mr. Liù, founder and major shareholder

of LK Machinery; I wanted to be

sure first of all that LK’s objective was to

relaunch and not to close the production

activities in Italy. But Mr. Liù had

clear ideas: he wanted to be the leader

of “low cost” presses n the Chinese

market, which already owned 60 %, and

also dominate the entire product range,

6 Casting Plant & Technology 4 / 2016


View into the production halls of

Idra, where a lean, process optimized

organization determines the production

of the die-casting machines

with Idra presiding over the segment of

high-tech presses for high-performance

components. All this could be achieved

only by keeping two distinct brands: LK

for low cost machines and Idra for highend

ones. No mingling between the two

realities, even at trade and finance network

level. The market had to understand

that LK was only playing the role

of shareholder. We would never have

sold Idra presses in our historical markets

or in China if the customer had

considered us “Chinese style”.

And this is how the adventure began,

at a time certainly not easy for the

metallurgical and manufacturing industry

in Italy and Europe.

I took the lead of the company in April

2009. I had to do it quickly and well,

the shareholder had no time and results

were expected to arrive soon to

prevent diversions. I had a good brand

and I had to have a good product. The

rest would have been supported by

the Chinese shareholder, Idra’s men

and my knowledge in the field. I convinced

the shareholder to invest in the

completion of the new series of OLS

presses in that year, the most difficult

for our industry, and I focused on commercial

markets where we could sell,

China first of all.

How did Idra achieve results immediately?

As a matter of fact, I still remember

the skepticism that hovered among

departments when I said that already

in 2010 we would have lost no money,

because we had everything to succeed:

brand, product, the thrust of “made in

Italy” and perfect shareholders for our

relaunch: an industrial group that understands

our product and the second

Italian bank to support us in relaunch.

I was right, we were able to reach

breakeven in just 18 months, eliminating

nearly 8 million losses, and making

Casting Plant & Technology 4 / 2016 7


K INTERVIEW

profits by 2011. I’ll take the credit for

bringing back confidence and enthusiasm

in a magnificent group of people,

the rest is thanks to them. With

these results, all were convinced of

the goodness of our choices, including

trade unions.

Certainly it hasn’t been easy to

achieve competitiveness.

It is true, Idra’s knowledge heritage

was a security to create cutting-edge

products, and perhaps it was more difficult

to bridge the competitiveness

gap on costs. Luckily I come from the

school of the great Teksid of the ‘80s

and I know that nothing happens by

chance, but everything has to be conquered

with fierce determination and

great passion, starting from the people.

When you start selling, that’s

when the difficult part begins, the

factory must follow you and adapt

to new paces, quality must always

be the focus of all choices and attention

to induced costs and waste must

be daily bread for everyone. Paying

my dues in production for years has

helped me, I could expect a lot from

my coworkers because what I was asking

them was what I used to do once.

Zero business flights, spending review

on everything, “lean organization”

without intermediates, hunting for

bottlenecks in the department to reduce

lead time for deliveries in shorter

times, outsourcing of non-core process

steps.

What about competition?

Today it is not enough to produce well,

you must offer a real competitive advantage

to your customers, you have

to think like them and offer them

what they need to overcome their

challenges. For example let’s consider

after-sales service; we sell durable

goods worth several some million

euros, whose investment return relies

heavily on production efficiency; in

other words, machines should never

stop and if they stop, we must be able

to reactivate the operation in zero

time. This is why we have focused on

remote control service, which is done

directly from Travagliato by tele-service,

without the need for one of our

technicians to go to our customer’s

home, often flying hours from our

offices. But this does not solve the

problem, if the service is related to

our Italian working time, so we created

three service centers, one in Italy

in our unique production site, one

in USA in Idra NA North America subsidiary

and a third in Idra China; so we

can cover 24 hours.

You have more than 9,000 presses

running for more than 1,200 customers

scattered in all parts of the world:

how do you ensure them all timely

assistance?

Without inventing anything, but

taking example from large multinationals,

we created a mixed support

network. We have three affiliates

abroad controlled 100% by us,

Idra NA North America, Idra Pressen

in Germany and Idra China, and we

have a number of Idra dealers in many

countries, able to offer Idra qualified

assistance. A presence that allows us

to better meet any request for assistance.

However, the secret is to make

sure that the customer doesn’t call us,

making him able to self-manage small

problems. We don’t want to earn with

assistance, nor have a customer who

is a “prisoner”, always relying on us,

we prefer having a competent customer

that understands our presses

and that manages them in complete

autonomy with the best satisfaction.

For this reason we teach our customers

for free what to do; in 2011 we inaugurated

ITC (Idra Technical Center)

which provides free professional

training courses to our clients. It’s a

big investment in terms of resources

and time, but it’s worth it because the

customer tries to solve his problems

with us and then he may apply what

has been learnt at his home.

You were talking about competitive

advantage as the goal to be reached

to sell your machines at remunerative

prices. Can we take a deeper look into

this topic?

Our competitiveness arises from Idra’s

approach to the market. When we ask

the question: which car will our customer

buy tomorrow, we immediately

try to know which products he must

provide for his end customers. In essence,

it is no longer enough to focus

on direct customer’s needs, but

we need to be farsighted and analyze

which pieces the client will produce

in the near future. Without this vision

we may set wrong strategies. Let’s consider

a very simple case: does it make

sense to develop a more advanced

press for the production of aluminium

radiators? Maybe not, maybe it’s useful

to invest elsewhere. At Idra we had

correctly evaluated the enormous development

of structural components

in light alloy castings in the field of

transport, and in advance of competition

and the current market boom

in 2010 we produced NoX presses (no

oxidation), able to work in high vacuum

conditions; without contact with

air aluminum can’t oxidize, and so

castings will not contain inclusions

of oxide or air entrapment, therefore

it can be subjected to heat treatment

to improve its mechanical properties,

as required by the designers of new

bodies and suspensions of cars. And

what’s more, demand is now directed

towards products with increasingly

thin walls, from 4 to 2 mm or less,

and so we have developed an injection

system that can develop more than

10 m/s speed in second phase also for

presses of more than 4,000 t, in such a

way that the alloy fills the mold cavity

very simply. And today the market

rewards us, just think about the

Ford Mondeo’s hatchback which is

produced only on Idra presses, or the

Mini’s knee blocker and the Range

Rover’s front.

Concerning the market outlook for

quality castings for the automotive

sector, there aren’t only structural

components, we also remember

continuous lightening of the engine,

which has focused the attention of designers

on light-alloy engine blocks;

do you have any developments and

news in this specific sector?

Today Idra has more than 100 presses

that produce light-alloy engine blocks

in all major car producing countries,

but I must say that we are particularly

proud for the order received from

8 Casting Plant & Technology 4 / 2016


Teksid from Fiat-Chrysler Group at

the end of 2013 as unique supplier

of new engine blocks for Italian and

Brazilian factories of the group. The

match was not easy: Fiat-Chrysler has

compared the best press manufacturers

and thoroughly analyzed all technical

and service aspects before making

its choice. There is no doubt that

other factors being equal, our technology

and after-sales service, which

are our flagship, have made the difference.

One last point: Idra is now 100 % Chinese,

with a unique shareholder that

has taken over remaining 30% first

owned by Intesa Sanpaolo. Aren’t

you worried about this situation?

In the light of my experience during

the last five years, I can assure you

that I am proud of this Italian business,

owned by a Chinese company;

it’s the clear proof that you can do

business in Italy, despite difficulties.

Funds are moved quickly from one

side to another of the globe, it is important

not to move production sites

and, in our case, it’s important for

Idra to keep thinking head and production

in Italy; this is why we don’t

worry, and results give us confidence

in this respect, we must just remember

that there are no situation rents

and that success must be conquered

day after day. China has represented

Idra’s salvation, frankly if my predecessor

hadn’t found a buyer willing

to invest in the company, today we

wouldn’t be here telling this small but

significant piece of company history.

Then we found on a silver platter the

keys of the Chinese market, with directions

on where and to whom to sell our

products in the years of profound crises,

I am referring to 2009 and 2010.

Without all this we would not have

had the necessary speed to balance our

accounts in less than two years. And

a good period awaits us, as long as we

continue working on innovation and

we maintain a positive gap compared

to competition.

www.idragroup.com

Casting Plant & Technology 4/ 2016 9


K MATERIALS

Authors: Gerd and Andreas Röders, G. A. Röders GmbH & Co. KG, Soltau; Stuart Wiesner, Rheinfelden Alloys GmbH &

Co. KG, Rheinfelden

Practical application of highstrength

alloy Silafont-38

The newly developed, high-strength alloy Silafont-38 was tested in a casting trial at the foundry

G.A. Röders, Soltau, Germany. In a thin-section structural casting, the material properties were

better than specified. Aspects examined in the context of the tests included the heat treatment

practice, the metallurgical properties, riveting and welding behaviour as well as corrosion resistance

of the alloy

In lightweight engineering of structural

components the requirements on material

properties are becoming increasingly

more exacting. One objective is to

achieve increasingly higher strengths in

order to build structures of ever smaller

section thicknesses. As a result of

optimizations in the pressure die casting

process and heat treatment practice,

the potential of the standard alloy

AlSi10MnMg has been continuously

widened. By modifying the alloy and

applying new heat treatment methods,

it is possible to even further expand the

applicability of this alloy.

The tested part

The tests were made on one of the structural

parts, which the foundry G. A. Röders

makes for Fastner Leicht metalltechnik,

Ilsfeld-Auenstein, Ger many, and which

is used in the Audi R8. Figures 1a and

b show the approx. 300-mm-long component.

It must meet the specifications

applicable to crash-relevant components

with section thicknesses of up to 2.0

mm. G.A. Röders produces this challenging

casting in series using the alloy Silafont-36

(EN AC-AlSi10MnMg). In addition

to the relevant material properties,

the part must provide good weldability.

Thin-walled structural component made of a high-strength Silafont-38 alloy tested

at G. A. Röders in a practical casting test (Photos and Graphics: Rheinfelden Alloys)

The alloy

When developing the alloy Silafont-38,

special emphasis was placed on castability,

which is more or less the same

as that of Silafont-36. The contained

zinc improves mold filling performance.

The addition of iron and manganese

reduces stickiness. Casting trials

have confirmed the good casting properties

of Silafont-38. Due to the alloy’s

good flowability, there was a slight tendency

towards greater flash formation.

However, the results of X-ray examinations

and blister tests were just as good

as those obtained from Silafont-36. The

increase in strength after a heat treatment

is predominantly due to a magnesium-copper

ratio, which suppresses the

development of corrosive phases. Highmelting-point

phases promote the formation

of ultrafine eutectic structures.

Heat treatment

In its technology centre, the foundry

Rheinfelden Alloys, located in southern

Germany, casts different plates and

a case with fins as test pieces. A comparison

was made between material properties

achievable in test plates of 3 mm

thickness and in structural castings with

extensive surface areas. While the similarities

in mold filling of such plates

and of large, high-quality structural

parts were greater than expected, there

were great differences in the quenching

rates of the castings after removal

from the molds and after the heat treatment.

Small plates can be quenched

at distinctly higher rates, with a corresponding

effect on the material properties.

For this reason, the heat treatment

was modified such that the quenching

conditions were very much like those

10 Casting Plant & Technology 4 / 2016


Figure 1: Front (a) and back (b) of

the component joined by rivets

a

b

found in industrial manufacturing processes.

Within the context of this simple

modification, the maximum quenching

rate was set at 3 °C/s. Figure 2 shows the

temperature curves of 3-mm plates under

different quenching conditions. The

measured material values correspond

largely to those measured in standardized,

industrial production processes.

Aluminium heat treatment specialists

Belte AG, Delbrück, Germany, applied

High Speed Air Quenching (HISAQ) and

an Aluquench treatment. The HISAQ

temperature curve, which was measured

by a trailing element, is shown in

figure 2. The Aluquench method uses

a polymer as quenching medium. The

corresponding temperature curve runs

very close to that of water quenching.

This method achieved very good material

values.

Material specifications

The target was to achieve a yield

strength of 180 N/mm² and an elongation

at fracture of at least 8 %. With

the casting technology developed at

the G.A. Röders foundry, the material

values were even better than specified

(Figure 3). Plotted here are the mean

values from approx. 50 tensile tests.

G.A. Röders boasts vast knowhow in

vacuum technology and in designing

and producing casting molds. For the

tests, only the alloy was changed, all

casting parameters remained the same.

Figure 2: Quenching tests

Riveting and welding

The strength of a material also has an

effect on its rivet setting performance.

Higher strength materials require different

rivets than materials of lower

strength. Therefore, the geometry and

parameters of the rivets were adjusted

to suit the properties of Silafont-38.

Thanks to the high ductility of Silafont-38,

the riveted joints are crack-free

(Figures 1 a and b as well as Figure 4).

The materials are joined by self-pierce

riveting, i.e. semi-tubular rivets set by

means of riveting tongs. G.A. Röders

Figure 3: Material specifications of Silafont-38

tested the weldability of the new alloy

by a welding test during production.

For the test, the respective area of the

material was fusion-welded by tungsten

inert-gas (TIG) welding and the surface

of the thus produced welded seam investigated.

Despite the zinc contained

in the material, this test showed that

weldability was just as good as that of

the standard alloy Silafont-36.

Casting Plant & Technology 4 / 2016 11


K MATERIALS

Figure 4: Microsection through the rivet

Figure 5: Microstructure in stage F

Figure 6: Microstructure in stage T6

Metallurgy and phase simulation

Figures 5 and 6 show microsections

of the part at a magnification of 500.

The stage designated as “F” is characterized

by an ultrafine eutectic structure,

which provides fairly good formability

already in the as-cast state. The

intermetallic phases are very small (below

10 µm) and evenly distributed. After

a T6 heat treatment, the eutectic

has a spheroized structure providing

for high ductility. Figure 7 shows the

quasistatic state simulated with the

JMatPro software on the basis of the

Calphad databases. The here presented

phases are generally large enough

to show in a micrograph. The Si-containing

eutectic phase plays a central

role in the alloy. A finely distributed

AlMnFeSi phase (alpha) is required

to achieve high ductility. Other highmelting-point,

intermetallic phases

influence the fineness of the microstructure.

In the investigated alloy, the

Mg2Si eutectic does not precipitate as a

Figure 7: Quasistatic phase simulation

major phase. Submicroscopic precipitations

in the aluminium phase have a

significant effect on the strength of the

material. Such precipitations can also

be calculated within the context of a

phase simulation by JMatPro. Figure 8

shows metastable MgSi phases, which

are decisive for the strength properties

12 Casting Plant & Technology 4 / 2016


of the material. The characteristics of

such phases depend on the initial material

state (as-cast or heat treated) and

the quenching conditions. If those

phases have the right size, they give

the material high strengths.

Corrosion resistance

A salt spray test under alternating conditions

(ISO 9227) and an intergranular

corrosion test (ASTM G110-92)

were conducted at the Steinbeis Centre

in Friedrichshafen, Germany. The

corrosive behaviour of 3-mm plates

made of Silafont-38 was examined

and compared with the corresponding

behaviour of other alloys provided

by Rheinfelden Alloys. Evaluations of

336 hours of salt spray testing showed

that the resistance to corrosion is appropriate

and similar, for example, to

that of Castasil-37 (AlSi9MnMoZr).

While high-purity alloys predominantly

corrode in the form of pitting,

Figure 8: Dynamic phase simulation

corrosion of Silafont-38 extends over a

wider area.

http://rheinfelden-alloys.eu

Casting Plant & Technology 4 / 2016 13


K MOLDING MATERIAL

Authors: Martin Dahlmann and Sabine Umla-Latz, Hüttenes-Albertus, Düsseldorf, and Joachim Wolff, Imerys Refractory

Minerals, Paris

High performance molding material

for most accurate castings

Complex cast parts such as turbocharger housings play a central role in the design of modern

high-performance engines. Due to its particular characteristics silica sand has its limits as a molding

material when it comes to casting finely structured components, reduced wall thicknesses

and perfect surfaces. Thanks to its high temperature load strength and a strong resistance to

metal penetration, Kerphalite KF, a special sand, has proven itself suitable for these types of applications

in many foundries

In central Europe, silica sand is available

in large quantities and in good

qualities, and is widely used in foundries

as an economical basic molding

material. But it also has negative properties,

which may lead to problems

when producing sophisticated castings.

These particularly include the socalled

quartz inversion, i.e. the abrupt

expansion of the specific volume at 573

°C. It occurs during virtually every casting

process and may lead to sand expansion

defects, mainly in the form of finning

(also called veining). The molding

material can crack under high temperature

load, allowing liquid metal to seep

into the resulting cracks and cavities.

Suitable alternative for silica

sand

Foundries aim to avoid these casting defects

and reduce the costly effort needed

Andalusite mining in Brittany, France. The name Kerphalite derives from the

Guerphalès deposit in Brittany (Photo: Imerys Refractory Minerals)

to rework the casting. This is all the more

important when considering that casting

geometries are becoming ever more

complex and the demands for their dimensional

accuracy and surface quality

are becoming ever more exacting.

If foundries want to avoid using more

binding agents or adding gas-forming

additives, they need a suitable alternative

to silica sand as a molding material.

Kerphalite KF is a special sand with

low thermal expansion, high refractoriness

and a special grain geometry that

enables very high core surface densities.

Figure 1: Andalusite crystals in rock (Photo: C.A.R.R.D)

Figure 2: The final product for use in the foundry in big

bags (Photo: Hüttenes-Albertus)

14 Casting Plant & Technology 4 / 2016


Mineralogical composition

Andalusite

Bulk density

1.55 g/cm³

Refractoriness SK > 36 ≥1830 °C

lin. expansion coefficient α 20- 600°C 6.5 · 10 -6 K -1

Average grain size

0.23 mm or 0.20 mm

AFS Grain Fineness Number 60 ± 5 or 70 ± 5

Grain form

angular

Core production

with all binder systems

Table 1: Properties of Kerphalite KF

Figure 3: Sand core for a turbine housing

(Photo: Harz Guss Zorge GmbH)

From stalky crystals to a special

sand

Kerphalite KF is a natural material based

on andalusite. Andalusite was first identified

in 1798 and named after the Spanish

province, Andalusia, though later

this location turned out to be untypical

for the mineral. In terms of its chemistry,

andalusite is an aluminium silicate

(Al 2

SiO 5

), which crystallizes in the ortho -

rhombic crystal system and usually develops

elongated, prismatic crystals with

a square cross-section (Figure 1).

When a water distribution network was

built in the north of Brittany, France in the

1960s, schist layers with aluminium silicate

inclusions – andalusite – came to light.

Today, Imerys Refractory Minerals

mines treats and processes the andalusite

in Brittany. The deposit is four kilometres

south of Glomel and comprises several

pits that are exploited in the form of terraces.

Imerys Refractory Minerals mines

about one million tons of stone per year.

At the end of the multi-step and highly

complex production process (breaking,

grinding, separating, calcination and

floatation), 80,000 tons of andalusite are

extracted. Several thousand tons of Kerphalite

KF are used as a special sand for

foundry applications across the world.

Processable with all binder systems

and molding processes

Kerphalite KF has a low density (similar to

silica sand) and can be used in pure form

or as blend with silica sand, as required.

When blended, the share of Kerphalite

KF should be between 30 and 100 %. In

this way, the user is able to adjust the sand

blend to be both cost-effective and process

efficient. The special sand blends are

easily processable with all common binder

systems. They are suitable for the Cold-

Box as well as for the shell molding process

or the furan no-bake process – in iron

as well as in steel castings. Kerphalite KF

has also been used for 3-D printing cores

for over ten years.

Strong partnerships for success

The partnership with Hüttenes-Albertus

has been decisive for the development of

Kerphalite as a special sand for the most

accurate castings in the European foundry

industry. In the mid-1980s, Hüttenes-Albertus

added Kerphalite to its product

portfolio, and has been actively promoting

the material’s advantages as a molding

material in the market ever since. HA’s

expertise in core production technology

as well as its extensive distribution network

have contributed to establishing

Kerphalite as a benchmark in the European

foundry industry. Today, the special

sand is used in a large number of foundries

in Germany, France and many other

European countries (Figure 2).

Dense core surfaces, low thermal

expansion

There are two special properties that

make Kerphalite KF a sought-after

molding material for difficult casting

jobs. First of all, the low and linear

thermal expansion plays, of course,

an important role as following example

shows: A 400-mm-long canal core

made of silica sand, if fully heated

to a casting temperature of 1380 °C,

would expand by a total of 9.3 mm.

This means the core either develops

thermal fatigue cracking resulting in

finning on the casting, or it bends or

breaks. However, when using Kerphalite

KF as a molding material, the core

would only expand by 3.8 mm under

the same conditions.

Secondly, the broken grains of the orthorhombic

crystal with their angular

cross section create a highly dense core

or mold surface. This effectively helps to

prevent the penetration of liquid metal,

especially in comparison to cores that

are produced from spherical sand grains

of the same average grain size (Table 1).

Proven applications in

foundries

Typical applications for Kerphalite KF are

cores for hydraulic valve housings, canal

and water jacket cores for cylinders and

cylinder heads, also subsections of the

water jacket core (as key core), as well as

cores for the helical turbine housing of

the turbochargers. In all of these cases it

is important to create fine, thin-walled

and dimensionally accurate casting parts

with flawless surfaces.

Foundries, such as Harz Guss Zorge,

Zorge, Germany, and many others, rely

on this special sand for casting turbine

housings and cylinder heads. The casting

has a complex geometry and has to

withstand high thermal loads to fulfil

its important function in the end product,

the turbocharger. The turbine housing

has to meet the highest quality standards

in order to achieve effective flow

behaviour. It is imperative to have a reliable

procedure to avoid finning, because

subsequent cleaning requires a lot of effort

or re-work is impossible (Figure 3).

When using Kerphalite KF as a molding

material, foundries are on the safe

side. They achieve a core with the lowest

thermal expansion and the highest surface

quality, able to withstand high casting

temperatures even in the most critical

areas: a core that meets all requirements

for producing a perfect cast part for a

high-quality, high-performance product.

www.huettenes-albertus.com

www.imerys-refractoryminerals.com

Casting Plant & Technology 4 / 2016 15


K MELTING SHOP

Author: Michael Dahmen, Otto Junker GmbH, Simmerath-Lammersdorf

Smart energy-efficient water recooling

system is successfully employed

in induction melting plants

For an induction melting furnace to operate safely, a powerful water cooling system must be in

place to prevent overheating of the induction coil, the frequency converter and the capacitors.

In this context, particular importance is attached to a low energy consumption of the cooling

water pumps and fans of the air cooler or evaporative cooler as well as to the capability of recovering

a large amount of heat from the cooling water

Typical pump frames of a water recooling system for a high-performance melting plant

(Photos and Graphics: Otto Junker)

16 Casting Plant & Technology 4/2016


Thanks to numerous developments,

induction furnace technology has

reached a high overall level of efficiency.

In cast iron melting, the efficiency

rate may amount to as much

as 75 % (Figure 1).

Power dissipation occurs mainly

in the form of ohmic losses from

the coil and electrical system, whereas

thermal losses are low. In cast iron

melting these ohmic losses amount

to approx. 20 - 25 % of the power input,

while for copper the figure goes

up to as much as 35 - 40 %. Thus, in

a cast iron melting furnace with an

8 MW power rating, the amount of

power dissipated as heat will be in

the order of approx. 2 MW. This high

amount of waste heat must be reliably

transferred away via a powerful

water recooling system to maintain

an appropriately low water temperature

in the supply line. Needless to

say, intense research efforts are being

made to reduce ohmic losses further.

Thus, reductions by 4 % and 9

% have been achieved, depending on

the metal being melted, through the

use of a special coil design.

A second option is to recover, and

hence re-use, the large quantity of

heat carried in the system’s cooling

water. It should be noted here that

heat recovery works best at an elevated

cooling water temperature which

should, moreover, remain as constant

as possible. At the same time,

the energy consumption of the cooling

water pumps and of the fans serving

the air cooler or evaporative cooler

should be reduced.

The basic parameters in rating a

water recooling system are the water

demand of the components to be

cooled, the maximum supply and

return temperatures, and the acceptable

temperature rise. In some

cases, two mutually independent

closed cooling circuits are employed

in view of the different water quality

requirements for cooling the furnace

and for cooling the electrical equipment

(converter, capacitors). Often

the furnace and the electrical system

are served by one common cooling

circuit, especially where IGBT converters

are used. The water recooling

system is dimensioned and its operating

regime is designed for the full

rated power of the melting furnace

plus a defined safety margin. The acceptable

temperature limits, which

amount to 85 °C for the furnace coil

and 45 °C for the electric circuit,

must not be exceeded.

As the cooling water pumps run at

full speed regardless of the amount of

heat actually dissipated, the system

continues to deliver its full cooling

output even in operating modes such

as, e.g., holding the melt at temperature

or shutting down the furnace. As

a result, the return water temperature

in the coil circuit will drop while

the electric power demand remains

unnecessarily high. The drawbacks

of this former practice can be summarized

thus:

» varying return water temperatures

» temporarily low temperature level

» unnecessary power consumption

of the pumps in the water recooling

system

The new approach

Together, Otto Junker und Induga,

both Simmerath, Germany, have

developed the intelligent water recooling

system referred to as SmartReCooler

(SRC) which adapts its

cooling output to the actual heat

losses of the induction furnace installation.

The system’s cooling output is

proportional to the temperature rise

and flow rate of the cooling water. It

supplies just the right cooling water

Figure 1: Typical energy flow diagram of a cast iron melting process

throughput for the current cooling

requirement, thereby maintaining

return water temperatures constant

and keeping the water recooling system

energy-efficient. Pump speeds

are determined by a smart controller.

As the control unit also takes into

account the furnace’s electric power

input, the cooling system responds

very quickly to new furnace operating

conditions.

In circumstances requiring only

little heat to be removed, e.g., when

the furnace is shut down and allowed

to cool over several hours, the system

runs in energy-saving mode. In this

mode it keeps up a minimum water

supply that suffices for all cooling

circuits. The SRC system can respond

autonomously to new heat loss sit-

Casting Plant & Technology 4/2016 17


K MELTING SHOP

Figure 2: SmartReCooler system screen

uations at any time. In energy saving

mode the cooling water pumps

draw very low power, i.e., very little

electricity is consumed. The energy

saving potential depends very much

on the furnace operating regime, i.e.,

on how long the furnaces are run in

holding or cool-down mode or with

reduced power input.

At KSB AG, the leading manufacturer

of pumps and pump systems, this

new technology was used on one of

two identically designed Monomelt

furnaces with independent water recooling

circuits which had been ordered

for the company’s Pegnitz site.

As one furnace plant featured the

smart SRC system while the other

was equipped with traditional water

recooling, the benefits of the new system

could be objectively evaluated.

The furnaces are designed to melt

both cast-iron and steel. Each of

the two plants consists of a 2-tonne

coreless induction furnace with an

IGBT converter rated for 1,500 kW.

The nominal frequency can be set at

500 or 125 Hz. The installations are

equipped with a JOKS melt processor,

a weigh scale, extractor hoods

and a hydraulic power pack.

The water recooling system of

each melting furnace has separate

cooling circuits for the furnace and

the electrical equipment and uses a

glycol-free water-to-air cooler. The

pump rack in the furnace circuit carries

two 7.5 kW pumps operating in

a redundant mode. The cooling cir-

IMERYS

REFRACTORY MINERALS

FOR FOUNDRY APPLICATIONS

INVESTMENT

CASTING

REFRACTORY FLOURS

& STUCCOS

SAND

CASTING

SANDS FOR

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FOUNDRY COATING

PUB IRM FFA EXE OK.indd 1 05/01/2016 11:58:36

18 Casting Plant & Technology 4/2016


cuit for the electrical equipment uses

only one pump of the same rating.

The water recooling system is controlled

by the furnace PLC via a remote

substation.

The extra hardware to be fitted for

the SRC system consisted only of

the variable frequency drive units

for the two furnace-circuit pumps, a

few temperature sensors, and some

small accessories. This was in addition,

needless to say, to the new

smart software developed for the application.

This software ensures that

the cooling water flow rate is adapted

at once when the cooling water

demand changes suddenly, e.g., because

the furnace is set to full power

by the operator or the load shedding

system. A simple control scheme

based on water temperatures alone

had been found inadequate. Figure

2 shows a typical screen menu, albeit

for a solution based on a water-to-water

cooler.

A water-to-water cooler fed from

the municipal water supply is fitted

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MOLOCHITE TM

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MULLITE &

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MULGRAIN ® 60

KERPHALITE TM

WHITE

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FUSED ZIRCONIA

MULLITE

in the electrical equipment cooling

circuit for the event that the air temperature

exceeds 30 °C and the water-to-air

cooler can no longer adequately

cool the more heat-sensitive

converter assembly. For heat recovery,

a plate-type heat exchanger is integrated

into the circuit.

By now the two Monomelt systems

have been in operation for five

months, and a first comparison between

the traditional and new water

recooling systems can be made.

Considering the different service

conditions of the two furnace systems

it can be said that the variable-frequency

drive units of the

cooling water pumps save a lot of

energy. Thanks to the use of the SRC

the energy consumption of the water

recooling system could be reduced

by more than 30 %.

Thomas Wagner of KSB AG’s Pegnitz-based

foundry production engineering

unit had this comment:

“The scheme using VFD-controlled

pumps in the cooling circuit has

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proved a full success at our site. In the

five months since the melting system

was commissioned, we have benefited

from a trouble-free operation and

substantial energy savings. In our

production conditions, we save so

much power that the extra cost of

frequency-controlling the cooling

pumps will be recovered within just

about one year. KSB AG now plans to

retrofit the second coreless induction

furnace, which does not yet feature

frequency control of the cooling water

pumps, to this new technology.”

Moreover, the new system has led to

higher and more constant water temperatures,

which augurs well for the

intended installation of a waste heat

recovery system.

Conclusion

The smart SRC system has successfully

proven itself in practice and the

specified targets were achieved. The

use of this control scheme clearly increases

the energy efficiency of a water

recooling system, apart from delivering

a constant temperature that

facilitates energy recovery. Further

benefits include a rapid adjustment

to the melting furnace’s operating regime

plus an extended service life of

cooling system components. In all,

the economic benefits yield a short

payback period. These advantages

are confirmed by the fact that KSB

AG now aims to convert its second

melting furnace to this technology

as well.

It remains to be noted that a conversion

of existing water recooling

circuits to the new system can take

place at short notice and with little

installation effort. Work is now

ongoing to realize this system for

Duomelt applications as well (two

furnaces, one frequency converter)

and a solution for controlling the

fans of the air cooler or evaporative

cooler is in preparation. The system

is also suitable for use on other water-cooled

thermoprocessing equipment.

www.otto-junker-group.com/de

www.induga.com

PUB IRM FFA EXE OK.indd 2 05/01/2016 11:58:40

Casting Plant & Technology 4/2016 19


K PRESSURE DIE CASTING

Author: Robert Piterek, Germany Foundry Association, Düsseldorf

The courage to carry out research

The pressure die-casting foundry Havelländische Zink-Druckguss GmbH & Co. KG in Premnitz,

Germany, is repositioning itself for the future with innovative research, automation and digitalization.

The company also wants to score with zinc as a light-construction material

A casting cell at HZD in Premnitz: the company has 100 personnel working on the die-casting machines, in processing,

in tool construction or in administration (Photos: BDG/Piterek)

For some time now a tree with filigree

zinc leaves has been standing at the German

Foundry Association in Düsseldorf

– on permanent loan from Havelländische

Zink-Druckguss (HZD) in Premnitz,

who used it to demonstrate their

competence in thin-walled casting at

the EUROGUSS trade fair in 2016. The

innovative company has one particular

aim: “the term ‘weight reduction’

should immediately be linked with

HZD,” Oliver Ganschar, the new Works

Manager of the zinc die-casting foundry

in western Brandenburg, puts it in a nutshell.

Ganschar and Commercial Manager

Raiko Hentze have recently become

the lead team of Petar Marovic, who last

year became Managing Director of the

foundry and started running it as the

Managing Partner in 2016.

The company has steadily grown

since its founding in 1991: the workforce

has increased to about 100 employees

today – a success story for the

structurally weak region on the River

Havel. HZD currently produces about

3,000 articles for roughly 200 customers,

making 3,000 tonnes of zinc castings

every year and increasing overall

sales to a current level of 17.4 million

euros. The zinc experts from Havelland

share the market with companies such

as HDO Druckguss- und Oberflächentechnik

GmbH in Paderborn, Adolf Föhl

GmbH + Co KG in Rudersberg-Necklinsberg,

and G.A.Röders GmbH & Co. KG

in Soltau.

22 die-casting machines with clamping

forces of between 7.5 and 200 tonnes

20 Casting Plant & Technology 4 / 2016


are at work in the production hall, mainly

models from foundry machinery constructor

Oskar Frech. The personnel

work in three shifts, producing castings

made of the zinc alloys Z410 and Z430 in

a weight range of between 0.1 g - 2 kg.

The customers come from the automotive

sector; the household appliances,

plumbing, fittings and drives industries;

locking technology and electrical

engineering.

Up to 40 castings are created with just

one shot when the permanent molds of

the die-casting machines close with a

hydraulic hiss and the hot zinc is shot

into the cavities. Batch sizes at HZD

range from 50 to several hundred thousand

units. Stay bearings, for example,

that are used for tipping windows, are

a classic of mass production. Either unmachined

parts or finished components

are delivered, depending on customer

requirements. When necessary, the

Premnitz-based company also sets up

and manages the supply chain.

At first glance, HZD is a completely

normal company like numerous others

in Germany. But something is different

here. This can be seen straightaway

from the many prizes that the SME regularly

sweeps up in the Zinc Die-Casting

Competition that is part of EURO-

GUSS in Nuremberg. This year, it was

second place for an in-house amplifier

in the ‘Substitution using zinc die-casting’

category. A two-piece aluminum

housing became a zinc component produced

in one casting. The substitution

also worked because the HZD design was

able to achieve the necessary screening

of the component (an in-house amplifier

that enhances cable connections

within buildings) in a less complicated

way than its predecessor. A development

reflected by the award.

The functionality of this sensitive

component was also assured by an innovative

deburring process which the

Oliver Ganschar (left) and Matthias Manns with the AMG gear lever made of

Zincopor. The feel of the gear lever is decisive for luxury cars from Mercedes-

-AMG

zinc die-casters from Premnitz swear

by: so-called cryogenic deburring, offered

by Mewo GmbH in Olpe, during

which components are cooled down

to -40 °C with the help of liquid nitrogen

(‘embrittlement’ in the jargon) and

then blasted with a granulate – reliably

removing the burrs without damaging

the casting. The cycle is over after 3 -

4 minutes. “The machine from Mewo

is reliable, and indispensable when a

casting is very thin-walled and there

are very tight tolerances,” according to

Ganschar. In addition to the cryogenic

deburring plant, HZD also operates

blasting units and centrifugal grinding

HZD won second place in the Zinc Die-

Casting Competition at EUROGUSS

with this in-house amplifier. The sensitive

component gets its finish using

cryogenic deburring technology

Casting Plant & Technology 4 / 2016 21


K PRESSURE DIE CASTING

Mewo Sales Manager Ralf Sinner with Matthias Manns in front of a separating

drum at the zinc die-casting foundry

Matthias Manns and Ralf Sinner by the cryogenic deburring plant with which

the in-house amplifiers are deburred. In front of them is the basket for bulk

goods, manually inserted in the machines

plants, and can carry out thermal deburring

of components if required by

customers.

A few years ago the ingenious casters

from Premnitz won first prize for

‘surface finish’ at the Zinc Die-Casting

Competition with a subassembly of

control levers and mechanical elements

for Bosch’s Tassimo coffee machine.

Another prizewinning part is the

C218 selection lever – a gear lever for

an automatic transmission. This convinced

both the jury and the customer,

Mercedes-AMG. The Premnitz foundry

won the prize for the production

process with their innovative material

Zinco por. “What mattered with this

component was staying below a particular

weight limit that would have been far

exceeded if solid zinc had been used,”

explains Ganschar. “A gear lever knob

that was too heavy would be forced

forward and trigger an unwanted gear

change during a sharp braking maneuver

because of the mass inertia. We were

able to prevent this with our light-construction

material Zincopor,” added the

Manager, who enters triathlon competitions

(swimming, cycling and running)

in his free time.

The patented material Zincopor is

a so-called ‘zinc foam’. In a sectional

view one sees numerous pores within

the casting but the surface is smooth.

“Weight reduction is the primary aim.

We achieve serial weight savings of

about 35 % using Zincopor,” explains

Matthias Manns, Foundry Manager at

HZD since the start of the year. Manns

is an imposing figure: tall and strong,

with a red beard braided into a plait and

a tattoo in the form of a Celtic cross on

one arm. One can well imagine him at

medieval markets, forging swords – or

casting zinc. “Mr. Seiler, the Technology

Manager, and I do not need any

name tags at trade fairs – people recognize

us from a long way away,” he says

laughing.

Manns has already been at HZD for

eleven years, working in the Technology

Department for the last five years

and therefore involved in the company’s

spectacular new developments.

Many other companies in the sector

steer clear of making their own developments

because such investments – without

an ultimate customer order – might

not pay in real terms. HZD, however, has

consistently expanded its competences

for casting very complex components

and developing materials, with four

developers in its Research & Develop-

22 Casting Plant & Technology 4 / 2016


Measurement technician Alex examines a small electronic housing with the new optical profile projector from

Keyence Deutschland GmbH, Neu-Isenburg, Germany

ment Department – supported by the

management. “Mastering complexity

is our advantage. Our research concentrates

on thin walls, precision and

surface quality,” says Ganschar. And

Manns adds: “We are also confident

about developing small complex electronic

products for which others have a

lot of respect.” The courage to carry out

their own research also involves a reasonable

attitude to mistakes: “One has

to be able to make mistakes when doing

research, in order to develop new

products – we learn from our mistakes,”

Ganschar is convinced. Until recently

he was also active as a research associate

at the Fraunhofer Institute for Industrial

Engineering (IAO) in Stuttgart.

Ganschar has serious ambitions for the

coming years. And change is necessary

because there have also been changes in

the fittings industry, one of the foundry’s

largest target groups: what used to

be a three-piece assembly is now made

up of 15 pieces. In addition to product

development, automation is very high

on Ganschar’s to-do list: “We are introducing

automatic casting cells and want

to get into light-construction robotics,

as well as low-sprue casting, and install

automatic inspection stations,” he says,

going through his list. He believes that

zinc is a thoroughly future-oriented

material, particularly because components

for automotive construction are

increasingly required to exhibit good

EMC behavior, high strength, low production

costs and good recyclability.

“We therefore expect that demand for

zinc components will increase sharply,”

he reveals. The company also has

expansion plans that extend beyond

Germany. Ganschar does not want to

go into detail here. But that is not all:

HZD also wants to be part of the digital

industrial revolution, i.e. Industry 4.0:

“We would like a digital image of production

so that we would always know

where the product is, though we would

still need workers as continuous problem-solvers.

But their job profiles will

rise in future so that they will be able

to handle the increasing automation

and digitalization,” he says thoughtfully.

The gradual change in the company

should not, however, become a burden

for the employees. On the contrary, the

company’s growth plan includes new

recruitment by the end of this year. New

personnel with foundry experience, an

understanding for material, and enthusiasm

for technologies and innovations

are being sought. Five apprentices are

currently being trained as machine and

plant operators, clerks or logisticians.

The workforce itself will undergo continuous

training so that the processes

become more efficient and productive

– because in Premnitz, too, no-one can

do without the scarce resource of skilled

workers!

www.hzd.eu

Casting Plant & Technology 4 / 2016 23


K PRESSURE DIE CASTING

Within the framework of a research project measures were taken to investigate the local microstructure improvement

of die-casting components (Photo: BDG/Soschinski)

Authors: Peter Hofer, Wolfgang Gössl, Klaus Peter Tucan, Reinhold Gschwandtner, Gerhard Schindelbacher and Peter

Schumacher, Austrian Foundry Institute ÖGI, Leoben

Tungsten-based composites as a

die material in high-pressure

die-casting

Local microstructure improvement in high-pressure die-castings (hpdc) by influencing thermal

and mechanical process parameters were examined. Within the examination of the cooling of

hpdc-tools the process related properties of the tungsten-based composite Densimet 185 (D185)

were tested. The scope of investigations involved trials in test facilities and the modelling of the

thermo-mechanical behaviour of the die material within the thermal-die-cycle. The results of the

investigations in the test facilitiy and the results of numerical simulation are presented. The material

D185 is compared with iron-based die materials

24 Casting Plant & Technology 4 / 2016


Introduction

Increasing cost pressure and increasing

quality standards lead to the necessity

of more efficient ways of process control

in the casting industry. Two of the

main cost drivers are tool costs and the

accumulating costs of high cycle times.

The main factor of die damage and severe

die failures are caused by process

related thermal stresses which are induced

by the alteration of heating the

tool surface being in contact with the

melt contact and cooling of the surface

by spraying and applying of the release

agent. The cycle time in hpdc is mainly

determined by the solidification time

of the melt in the die which itself is dependent

on the heat transfer through

the die material. From these considerations

it can be seen that both – thermal

shock and solidification time –

can be influenced positively by the

use of materials with a high thermal

conductivity. In the recent past steel

manufacturers have introduced new

steels with high thermal conductivities

as materials for hpdc-tools. Apart

from these materials a variety of materials

based on refractory metals such

as tungsten and molybdenum based

alloys exist. These materials show a

constantly high thermal conductivity

over the entire range of application

temperatures of typically 250 to 500 °C

whereas conventional, iron based materials

often show a decrease of thermal

conductivity with increasing temperature.

Tungsten and molybdenum

based alloys have been used in gravity

and low-pressure die-casting tools for

several years. The excellent rate of heat

removal which is achieved makes them

interesting candidates for hpdc-applications

even although the material

costs are clearly higher than those of

conventional materials. In this work

the tungsten-based compound alloy

Densimet 185 (D185) produced by

Plansee Corp, Reutte, Austria, is being

investigated closely and compared to

the conventional tool steel 1.2343.

Theory - Heat transfer in

hpdc-tools

During the solidification of melt in

a permanent die the heat is removed

by the mechanisms of heat transfer

Heat transfer coefficient in Wm -1 K -1

100

80

60

40

Densimet 185

Rovalma HCTS 130, annealed [2]

20

1.2343, hardened

0

0 100 200 300 400 500

from the surface and heat conduction

through the die material. The amount

of heat removed in a certain time span

(power of heat removal) is dependent

on the following parameters:

» the coefficient of heat transfer (HTC)

measured in W/m²K at which 1 W/

Temperature in °C

Figure 1: Comparison of the heat conductivity of three different materials

used in hpdc-die-fabrication (Graphics: ÖGI)

Figure 2: Schematic view of the used test facility

m²K is the amount of heat which

is transferred per second over a one

square metre large interface when

the temperature difference is one

Kelvin and

» the heat conductivity measured

in W/mK at which 1 W/mK is the

Casting Plant & Technology 4 / 2016 25


K PRESSURE DIE CASTING

amount of heat which is transferred

per second through a static fluid or

a solid body when the heat gradient

is one Kelvin per metre.

Heat conductivity is an intrinsic thermo-physical

material parameter which

itself is temperature dependent. The

heat transfer coefficient in the opposite

is a model parameter. Commonly

heat transfer is calculated as follows:

Q˙ = α · A · ∆T k

(Equation1)

Figure 3: Test procedure and temperature curve during the trials at the test

facility (schematic)

Figure 4: Comparison of the results from the trials with water as a cooling

medium and a single spiral core (SSC)

where Q˙ is the heat flow, A is the contact

area fraction, ∆T is the temperature

difference between the contact

partners and α the heat transfer coefficient[1].

Heat transfer through a solid is determined

by Fourier’s law of heat conduction.

In its simplest form it describes

the stationary heat transfer through a

wall (Equation 2):

Q = ––

l

· A · DTw·

d

(Equation 2)

where Q˙ is the heat flow, A the area of the

wall, ∆T is the temperature difference between

the two sides of the wall and λ is

the heat conductivity of the wall material

[1]. Equation 2 also approximates the

heat flow from a die surface to a cooling

channel if the temperatures are set to average

values over one cycle.

Typical values (in steel dies) for the

variables in Equation 1 and 2 are:

α…….....10,000 W/m²K

A…….....0,1 m²

λ…….....40 W/mK

∆T_k…..400K

∆T_w….100K

d…….....0,1 m

After applying these values into the

Equation 1 the result is

Q˙ = 400 kW (Equation 3)

Figure 5: Comparison of the results from the trials with oil as a cooling medium

and a single spiral core (SSC)

which is the heat transferred from the

melt to the die surface.

It has to be considered that this is

only valid for the first few moments

after the metal is injected into the die.

With progressing solidification the

amount of transferred heat is reduced

due to a decreasing ∆T_k and the for-

26 Casting Plant & Technology 4 / 2016


Figure 6: Meshed geometry, red:

melt, blue: die

Figure 7: Calculated temperature distribution after the end of solidification,

left: 1.2343, right: D185

mation of a solid shell, leading to an

additional heat resistance.

For the heat transported through the

die material the result is

Q˙ = 4 kW.

It can be seen immediately that the

amount of heat transferred to the die

surface is much greater than the amount

of heat which can be removed by the die

material. The same situation is given

when the die surface is quenched rapidly

by die spraying. In the case of die

spraying the heat amount induced by

water eva poration is also much greater

than the heat which can be transported

to the die surface. These circumstances

lead to the formation of temperature

peaks and subsequently to peaks

in the thermal stresses especially at the

surface of the die. The abrupt change

of compressive and tensile stresses at

the die surface is a well-known mechanism

leading to fire cracks. A second

effect of the limited heat conduction is

that the cooling rates that are achievable

by the implementation of cooling

channels are limited by the die material.

Higher thermal conductivity of the

die material would lower the stress and

temperature peaks and also potentially

lower cycle times. Therefore benefits

can be expected for both die life time

and productivity.

Comparison of heat conductivities

As already mentioned materials with

higher heat conductivities than the

most commonly used die material, the

hot working steel 1.2343, have been developed

in the recent past. One example

is the material HTCS 130 which

was developed by Rovalma S.A., Barcelona,

Spain. The heat conductivity of

this steel at room temperature is close

to that of pure iron so that it almost

reaches the theoretical limit for iron

based materials. The thermo-physical

properties at room temperature and

elevated temperatures have been published

in [2]. If the heat conductivity

potentials of iron based materials become

insufficient for a certain purpose

one has to switch to other material

families. One possibility is the use

of tungsten or molybdenum-based alloys.

Their heat conductivities are way

higher than that ones of iron based

materials. Figure 1 shows a comparison

of the heat conductivities of the

materials 1.2343, HTCS 130 and D185.

(All data in figure 1 were obtained at

the Austrian Foundry Institute). It is

remarkable that the heat conductivity

of D185 is almost constant over the

whole temperature range. This is quite

advantageous for the hpdc-process.

For that reason D185 was tested more

comprehensively in technological test

facilities representing industrial hpdc-conditions.

Experimental – Trials at the

test facility

In order to quantify the heat removal

capacities of different cooling concepts

in hpdc with respect to cooling

media (water, oil), flow properties and

geometries as well as die materials a

test facility was developed at the Austrian

Foundry Institute. The trials with

D185 were part of a larger investigation

programme with different die materials.

The results of this series of trials

with several iron based materials have

been published in [3] and [4]. The testing

concept is similar to that presented

here.

Each testing device consists of an axially

symmetrical body which is fabricated

from the material which is requested

to be tested. This body is heated

up to a pre-set temperature of 260 °C

by a conventional oil tempering device.

The heat input of the liquid metal

is simulated by six electrical cartridge

heaters. In the center of the body is a

bore hole where the cooling medium is

passing through. The cooling media are

directed by different standardized flow

geometries. Figure 2 shows a schematic

view of the construction. The body

has 18 positions for thermocouples logging

temperature values at six different

distances from the surface of the bore

hole and at three different length positions

of the bore hole. A more detailed

description is given in [3].

The trial itself is divided into 5 stages:

» Preheating of the body via oil tempering

up to 260 °C,

» Heating up to 350 °C via oil tempering

and cartridge heaters,

» Activating the cooling at active electrical

heating with cartridges until

an equilibrium temperature T equ.

is

reached,

Casting Plant & Technology 4 / 2016 27


K PRESSURE DIE CASTING

» Deactivating the cooling, reheating

(as in step 2) to 350 °C,

» Deactivating of the cartridges, activation

of the cooling and cooling

down the facility to ambient temperature.

These stages as well as a corresponding

temperature curve are shown in

Figure 3. The removable amount of

heat for a certain experimental setting

can be derived from the equilibrium

temperature T equ.

and the slope k of

the cooling curve. The lower the value

for T equ.

and the higher the value of k,

the higher is the amount of removable

heat per given time span.

Surface temperature in °C

400

350

300

250

200

150

100

Experimental results

The results of the trials are shown in

the Figures 4 and 5. The presented

values are the cooling rates in stage 5

(k-values) for water cooling (figure 4)

and oil cooling (figure 5) in two different

distances from the surface of the

drill hole. Tungsten-based D185 shows

the highest k-values for both, the oil

and the water tempering, which is due

to its higher thermal conductivity with

respect to steel. Heat can be conducted

through the material much faster.

The effect appears clearer when the

heat transfer to the cooling medium

is higher due to the fact that the limiting

effect of the die material is greater

Figure 8: Material D185, stress parallel to surface at the end of solidification

(left) and at the end of the spraying process (right)

Temperature W300

Temperature D185

Stress W300

Stress D185

Mormalspannung in MPa

200

100

0

-100

-200

-300

-400

0 10 20 30 40

Time in s

Figure 9: Comparison of temperature and stress evolution for the materials

1.2343 and D185 in the hpdc-cycle (cycle data from Table 1)

Normal stress im MPa

the greater the difference between convective

and conductive heat is. To this

effect the obtained differences were

greatest in the trials with water cooling.

Simulation study – thermal

stresses in hpdc-tools

After the higher heat removing capacity

of the material D185 was confirmed

via the trials at the testing facility,

a principal study on the thermal

behaviour and the corresponding stress

behaviour of D185 in the hpdc-process

was done. The aim of this study was to

determine how the different heat conductivities

of D185 and 1.2343 result

in differences in the thermo-mechanical

loads of a die. For all simulations

the commercial software ANSYS Workbench

14.5 was used. The overall concept

is vaguely based on former works

by Pierri and Richter [5]. The model

represents a 2-dimensional section of

a hpdc-tool which is thermally loaded

by the heat input of an Al-melt with

6 mm wall thickness. The cooling

channel has a diameter of 12,5 mm.

The meshed geometry is shown in

Figure 6. As a first step a transient

thermal calculation of the temperature

field was conducted. The thermal cycle

times are shown in Table 1. The heat

transfer coefficients used in the simulation

are shown in Table 2. As a cast alloy

a simplified version of an AlSi-alloy was

used for the melt. For the die materials

1.2343 and D185 data sets were generated

based on the data provided by the

manufacturers and data measured at

the Austrian Foundry Institute. The initial,

homogeneous temperatures of the

melt were set to 650 °C, while the die

temperature was set to 210 °C. Figure 7

shows the calculated temperature distributions

for 1.2343 and D185 right after

the end of the solidification of the

melt. The isothermal lines in figure 7

show that the heat removal in the die

made of D185 is clearly higher. This has

also an observable influence on the solidification

time.

Subsequently to the calculation of

the temperature field a static mechanical

calculation based on the temperature-field

calculation was performed.

The calculated temperature fields at

each time step of the thermal calcula-

28 Casting Plant & Technology 4 / 2016


Process step

Cavity filled, die closed, solidification

Die open, waiting, ejection of casting

Spraying

Blowing

Die open, waiting for die closing

Die closed, waiting for shot

time

0-10 s

10-20 s

20-22 s

22-24 s

24-30 s

30-40 s

Table 1: Cycle data for the simulation of the heat balance

Heat transfer pair

Heat transfer coefficient in W/m²K

Melt - Die 10,000

Spraying medium - Die 10,000

Blowing air - Die 250

Ambient - Die

temperature dependent

Oil channel - Die 2500

Table 2: Heat transitions in the individual process steps

tion were applied as thermal loads at

each time step of the mechanical simulation.

As only one load cycle was taken

into account the material behaviour

was supposed to be linear elastic. Figure

8 shows the surface stress (parallel to

the die surface) of the die made of D185

at the end of solidification and after

quenching the surface via the spraying

process. Corresponding with the thermal

load of the die surface at the end

of the solidification the surface suffers

compressive stress. After the ejection of

the casting and subsequent spraying of

the die the temperature gradient is reversed.

Because of the increased base

temperature of the die far away from

the surface the reversed temperature

field leads to tensile stresses. At the die

surface the tensile stress has its highest

level which could lead to the initiation

of fire cracks in reality. Figure 9

shows a comparison of the time-stress

curves for the materials 1.2343 and

D185. In figure 9 it can be seen that the

temperature and corresponding stress

peaks are much lower in D185 than in

1.2343. Under real conditions the surface

stresses are overlapped with chemical

reactions between melt and die material.

However these effects have not

been taken into account in this work.

Conclusions

Due to its increased heat conductivity

with respect to steels a better heat removal

and a better resistivity against

thermal shocks may be expected by using

D185 in hpdc-applications. These

expectations were proven in test facilities

and by numerical modelling. The

following conclusions may be drawn:

» The obtained cooling rates for tungsten

compound D185 at the test facility

are higher than that of iron

based materials,

» the calculated solidification time using

tungsten compound D185 is lower

than observed for steel 1.2343,

» the calculated temperature peaks for

D185 are lower than that for steel

1.2343

» due to the decreased temperature

peaks decreased stress peaks may be

expected.

It has to be considered that the direct

prediction of damage initiation and

die life time cannot be derived from

the simulations done in this work. This

is due to the fact that the thermo-mechanical

fatigue and the plastic material

behaviour of the materials were

not taken into account. Nevertheless

a positive effect of the decreased loads

can be expected.

References:

www.cpt-international.com


K AUTOMATION

Author: Klaus Vollrath, Aarwangen, Switzerland

The Olsberg foundry modernizes

production of castings

New HWS molding line provides greater flexibility and higher quality

Olsberg GmbH, an SME based in the

town of the same name in North-

Rhine Westphalia, has invested about

11 million euros in new state-of-the-art

plants for the production of castings.

At the heart of the investment lies a

powerful molding line which, compared

to the previous equipment, can

meet considerably higher demands

regarding the complexity and quality

of the castings made with it. Heinrich

Wagner Sinto Maschinenfabrik (HWS)

from Bad Laasphe was selected as the

partner for this modernization pro ject,

which took two years and involved

deep interventions in the structure

and processes of the company. Apart

from the performance of the new plant

technology, a major reason for choosing

HWS was the mutual trust that has

developed during a decades-long collaboration.

The molding line from Heinrich Wagner Sinto has separate drag and cope

box lines (Photos and Graphics: HWS)

Aligned towards customers in

European machine construction

“The new molding plant is an important

and long-term investment in our

future,” said Ralf Kersting, Managing

Partner of Olsberg GmbH, during inauguration

of the new production

line at the company’s headquarters

on 23 September 2015. The foundry

is the nucleus of the family company

that is almost 440 years old and has

developed from a smelting works for

domestic ore into a producer of both

industrial products made of cast iron

and sheet metal as well as a specialist

for heat generation from renewable

energies based on firewood and

pellets. Whereby its work as a jobbing

foundry is a vital economic mainstay.

The Olsberg foundry supplies a large

number of well-known industrial customers

with serial and hand-poured

castings using cast iron with lamellar

and spheroidal graphite.

It has two molding plants on

which molds are made for complex

parts with unit weights of from

1 kg to a maximum of 500 kg and a

molding box size of 1500 x 1100 x

500+50/500 mm. The range of activities

also includes comprehensive

surface treatment, and partial or full

processing as well as extensive logistical

services. With the new molding

line, which replaces the previous

37-year-old Molding Line 1 from the

same producer, Olsberg is orienting

itself more strongly towards customer

requirements in European machine

construction.

Demanding market environment

The market for such castings is highly

competitive internationally. Numerous

suppliers are active in countries

that have considerable advantages over

German producers regarding wages, in

particular. This primarily affects cheap

mass-produced parts. In order to be able

to keep pace here one must exploit one’s

own strengths and push them as far as

possible to the limits. German suppliers

whose most important advantage

is their highly qualified and motivated

employees therefore capitalize above

all on high-quality castings with a high

level of difficulty and demanding quality

requirements. In the case of Olsberg

GmbH these also include, in particular,

thin-walled housings for electric mo-

30 Casting Plant & Technology 4 / 2016


tors with demanding geo metries and

strongly pronounced ribbing. Another

aspect is the serial batch sizes, because

the above-mentioned strengths of domestic

companies are particularly important

for small to medium-sized series.

The decision to purchase the new

HWS molding line was therefore not

made in order to expand production

capacity but, above all, to optimize

the ability to make technologically demanding

products with high quality

and flexibility regarding dimensions,

weight and serial batch sizes.

Obsolescence of the previous

molding plant

“The old Molding Line 1 provided,

for example, too little space for insertion

of the cores in the casting molds

to produce more complex components,”

explains Dr. Volker Schulte,

Technical Manager at Olsberg. In addition,

the cooling times for larger and

thicker-walled components, in particular,

were too short – leading to an

unacceptably high defect rate. This is

because the old molding line was originally

designed for a different product

range. Because a jobbing foundry

has to follow the market, these design

weaknesses became increasingly noticeable

with the ever-greater alignment

of casting production for machine

construction. As the design was

pre-determined as a result of the original

concept of the plant, it was impossible

for the company itself to make

corrections by undertaking comprehensive

renovations.

The new molding line

“We decided on a molding line technology

that would be optimum for meeting

future market demands,” according

to Dr. Schulte. The company will thus

be available to future customers as a reliable

systems supplier. The heart of the

complete solution supplied by Heinrich

Wagner Sinto is a plant for mold compaction

that operates using the Seiatsu.plus

airflow squeeze press-molding

process. This ensures excellent and

even compaction of the mold material,

even in critical areas with large projections

or tight ribbing. The main innovations

compared to the old molding

During inauguration at the Olsberg headquarters Technical Manager Dr.

Volker Schulte, The Employment Minister of the German state North-Rhine

Westphalia Guntram Schneider, Foundry Manager Ulrich Herrmann and Managing

Director Ralf Kersting (from left to right) initiate plant operation in

front of guests and employees

The casting of thin-walled housings for electric motors with demanding geometries

and strongly pronounced ribbing makes major demands on training

and qualification at the foundry

Casting Plant & Technology 4 / 2016 31


K INTERVIEW

even and lower internal stress level.

The availability of 19 spaces for manual

casting and 15 for the use of an automatic

casting machine also offers

greater flexibility. The molding box

size is 1025 x 775 x 300+50/300 mm

with a performance of 120 complete

molds per hour.

View of the heart of the new molding line. In the center of the picture, on

the front left, are the prepared patterns for drag and cope boxes, to the right

of them is the compaction station using the Seiatsu.plus airflow squeeze

press-molding process

Compressed air flows through the mold material from above (left) and accelerates

it in the direction of the pattern plate. The sand thus achieves maximum

pre-compaction in the layers closest to the pattern. The mold retains its

strength through re-compaction with a multi-plate press whose pressure can

be adjusted (right)

line include equipment for the automatic

change of patterns, increased

flexibility during rapid product changes

or for small series, and the increase in

the number of core insertion spaces to

eleven (of which nine are for drag boxes

and two for cope boxes). This permits

the creation of considerably more complex

geometries than before.

Another important advantage compared

to the old plant is the much larger

cooling chamber. The subsequent

longer cooling time benefits casting

quality, for example through a more

Self-adaptive mold material

compaction

One outstanding feature of the new

molding line is the Seiatsu.plus process.

This is a further development of

the long-established Seiatsu process,

based on the combination of airflow

compression of the mold material followed

by re-compaction by means of

numerous individual punches using a

shared hydraulic drive. The extended

mold machine elevating platform with

the pattern plate carrier is mechanically

interlocked during the entire compaction

process by means of the proven

wedge support system, so it cannot

move downwards. In the new process

variant, a special frame element (leveling

frame) provides additional compaction

of the pattern side – and thus

a considerable improvement of mold

hardness, particularly in the peripheral

areas of the mold. Another feature of

the system is a flexible choice between

normal pressing with the multi-plate

press, use of the airflow with the multiplate

press, use of the supplementary

Seiatsu.plus compaction, or an individual

combination of these variants.

Every molding box therefore receives

optimum compaction.

Selection criteria: performance

and trust

The implementation of a project of

this magnitude was an enormous task

for a medium-sized company like Olsberg.

Not only this, but one also had

to cope with restricted works grounds

that are veritably squashed between

two hills and with structures that have

grown over very many years and are

closely intermeshed with one another.

Fitting the plant in the existing conditions,

and coordinating the demolition

and building work, presented major

challenges for all concerned. In such

pro jects it is important to prevent sit-

32 Casting Plant & Technology 4 / 2016


uations requiring adaptations and corrections

to the original planning. In addition

to pure performance and price

criteria, there was also the question of

which suppliers could be sufficiently

trusted to handle even unforeseen situations

as a partner. This was one of the

decisive reasons for choosing HWS. Olsberg

had already had very good experiences

with this plant producer over decades.

Complicated construction

phase

Great attention had to be placed on the

existing space situation when planning

the molding line. Numerous modifications

to the usual arrangement of the

various plant components were necessary.

Supports, absorbers and transfer

equipment had to be adapted. In

addition, several plant sections had to

be produced as special versions. The

hall roof had to be raised to fit the enlarged

cooling plant for the cast molds.

The task of carrying out all the building

measures – including the demolition

and reconstruction of the building

under cramped conditions whilst maintaining

running operation of the foundry

– proved to be a particular challenge.

The new molding line was planned and

constructed in two stages in order to

minimize work interruptions. During

the first phase, plant components were

constructed and installed in the old pattern

construction area so that the existing

old line could continue production

during this time. In the second phase,

the old molding plant was demolished

in a few days and, following the foundation

work, the remaining part of the

new installation was quickly mounted

and commissioned together with the

completed first phase.

Building on restricted works grounds that are veritably squashed between two

hills and with structures that have grown over very many years and are closely

intermeshed with one another was a particular challenge (Photo: Olsberg)

All this required profound conversion

and expansion measures. First, a new

warehouse was built for foundry auxiliary

materials and a bypass road built

for the future hall. In order to be able

to maintain running operation, a new

piece of hall was docked at the west

end of the old hall and then building

work was carried out above the existing

hall. This was then about three meters

taller and 14 meters longer than the

former building. After that, a part of

the old hall was taken down, and the

old molding plant was dismantled and

finally replaced by the new line.

Investment in the future

“With the decision to invest this, for

us, large sum in the foundry in Olsberg

we are reconfirming our commitment

to this location and to our qualified

employees,” says Ralf Kersting. The

investment is intended to secure the

company’s existence at this site and

successfully expand it. It is often asked

whether Europe will remain a production

location in future or simply become

a pure development location for

others. The Olsberg company has undertaken

to continue being successful

in the production location of Germany

– with its excellent workforce and

technologically advanced suppliers.

With this decision, however, they are

trusting that politicians will continue

to ensure fair energy and economic

conditions in Germany. Only in this

way does a company have a chance to

remain internationally competitive.

www.wagner-sinto.de

www.olsberg.com

The new molding line

The new plant should improve, in particular, the possibilities of producing extremely demanding cast components made of cast

iron with lamellar or spheroidal graphite (GJL / GJS). Casting is carried out in bentonite-bonded molding material; the performance

is 120 complete molds per hour with a forming box size of 1025 x 775 x 300+50/300 mm. The forming sand requirement

is 99 tonnes per hour (at 120 molds per hour). There are nine core insertion spaces for open drag boxes and two for

open cope boxes. In addition to 19 manual casting spaces there are also 15 casting places available for the automatic casting

machine to be installed later; the cooling time is about 105 minutes. Pattern changes take place automatically. The drag boxes

are transported on line carriages for core insertion. The compaction of molds takes place with the help of Seiatsu.plus airflow

squeeze press-molding, whereby a specific press force of maximum 150 N/cm² can be set. The maximum bale height is

250 mm and the separation distance when lowering the pattern is 550 mm.

Casting Plant & Technology 4 / 2016 33


K SIMULATION

Authors: Wang Houming and Wu Shiguang, Shanghai Sandmann Foundry (SSF)

Optimization of a brake caliper

Due to safety reasons, brake calipers are produced to the highest quality requirements. The

Shanghai Sandmann Foundry (SSF) developed, and is successfully producing a car caliper made

of spheroidal graphite cast iron (GJS) which was acquired to be optimized in a Disamatic casting

process.

Brake caliper, optimized with

MAGMA 5 (Photos and Graphics:

Shanghai Sandmann Foundry (SSF))

Figure 1: Problems in the area of the hydraulic cylinder: shrinkage cavities and

sand inclusions

At the time of acquisition, the caliper

was being made in a six-cavity layout

with the cylinder axis in a horizontal

position. During mass production

the amount of scrap had increased,

especially due to unacceptable levels

of shrinkage porosity and sand inclusions

in the critical area of the hydraulic

cylinder (Figure 1), discovered

during X-ray examination. These defects

were strongly influenced by the

layout of the part in the mold. According

to the engineers of SSF, a change

of the casting orientation was required

in order to produce the part economically,

while fulfilling all quality criteria

and following the given constraints.

At the beginning of the optimization,

the experts used MAGMA 5 to understand

the problem observed in the

original layout. The tendency to form

shrinkage porosity in the feeder neck

area could be confirmed. However,

eliminating the problems by simply

making adjustments to the feeder or

feeder neck was not possible, due to the

technical constraints on the pattern.

Therefore, further changes in the

casting layout were necessary. Based

on the experience of the SSF experts,

the impact of rotating the component

by 45° in the mold was assessed with

the help of MAGMA 5 . To rotate the

parts, the feeders had to be changed to

a spherical shape, something that SSF

had already been using successfully for

other castings. These modifications

helped to shift the porosity away from

the critical area. However, the change

also had a negative impact on the

mold filling. An increase in turbulence

Company Profile

The Shanghai Sandmann Foundry (SSF) Co., Ltd. is a subsidiary of Huayu Automotive

Systems (Holdings) Co., Ltd., located in the International Auto City Anting

Shanghai. They manufacture spherioidal and lamellar cast iron (GJS and GJL) and

CGI castings for the automotive industry, with an annual production of 160,000 t

and a turnover of 1.9 billion Euros. Production is mainly performed on three Disamatic

lines and one HWS line. They also have a dedicated test foundry and a shell

molding facility. Customers of SSF include automotive OEMs worldwide.

34 Casting Plant & Technology 4/2016


Figure 2: Original (left) and optimized version (right) of the casting layout

Figure 3: The ,Hot-Spot FSTime’ quality criterion shows that the process is not robust (left). ‚Hot-Spot FSTIME‘ after

changing the casting layout (right)

during filling was observed, which led

to a higher risk of sand inclusions.

To also solve this problem, the impact

of an additional overflow and various

geometries for gating and feeding

had to be checked. Through traditional

simulations, this would have resulted

in several versions and a lot of manual

work, but the experts at SSF made

use of the new metho dology of Autonomous

Optimization in MAGMA 5 ,

which played a crucial role in finding

the optimal design (Figures 2 and 3).

The optimization parameters were

parametric geometries for the feed-

Casting Plant & Technology 4/2016 35


K SIMULATION

with/without

Overflow 1

with/without

Overflow 2

Feeder

Geometry

Smooth

Filling

Reduce

Porosity

Figure 5: Overview of all designs, linked with the objectives in a parallel coordinates

diagram

Figure 4: Parametric geometries -

overflows and ball feeder as variables

of the experimental design

Smooth

Filling

Reduce

Porosity

ers, gates and optional overflows

( Figure 4). With this, 10 designs were

defined and calculated automatically

as a virtual experiment in MAGMA 5 .

At the same time, a smooth filling and

minimum of porosity were specified as

objectives for the optimization.

With the help of the statistical tools

in the assessment perspective of MAG-

MA 5 , the engineers were able to evaluate

the complex filling behavior efficiently

and within a short period of

time. While a traditional comparison

of conventional 3-D results did not

allow clear conclusions, the experts

were able to identify the main influencing

factors on the casting quality

by using the correlation matrix. In

addition to this, the optimal solution

was quickly determined with the help

of the parallel coordinates diagram

(Figure 5).

In the correlation matrix (Figure 6),

the comparatively small influence of

the overflows on both an optimized

Feeder

Geometry

Figure 6: Linking of process variables and quality criteria in the correlation matrix

with/without

Overflow 2

with/without

Overflow 1

feeding and a smooth filling was made

visible. By contrast, the feeder size

had a much more significant impact.

Through an increase of the feeder volume

by 3 %, the best compromise for

both objectives was identified. The final

X-ray examination of the castings

which were produced with the modified

design delivered a positive result

for all areas.

The systematic investigation of various

options by the Sandmann experts

built the basis for a successful mass production

of the caliper. Through the

implementation of the optimized layout

for an annual production of about

840,000 sound castings, around 384

tonnes of raw materials could be saved.

Reduced machining work and energy

savings led to more than 75,000 euro

in sa vings, and the scrap rate was reduced

by a factor of 10.

www.magmasoft.com

36 Casting Plant & Technology 4/2016


The new, environmentally friendly AMR (Aeration Molding Robot Pouring) facility at Georg Fischer GmbH in Mettmann

for the production of automotive lightweight components made of ductile iron (Photo: Andreas Bednareck)

Author: Douglas Trinowski, Westmont, Illinois, USA

Comparing molding and core making

trends in the U.S. and EU casting

industries

While there are differences between European and U.S. foundries, those differences are getting smaller.

Environmental rules and regulations will continue to influence foundries on both sides of the Atlantic

Some trends bear closer scrutiny:

REACH regulations may have a significant

impact on the use of certain

binders in the EU. As the U.S. adopts

such regulations, as it has with GHS

(Globally Harmonized System of Classification

and Labelling of Chemicals),

those impacts will be felt by suppliers

and foundries alike.

European automotive OEMs have led

the push for inorganic binders, and were

willing to take the time and spend the

money needed to successfully implement

this technology into serial production.

The next challenge is to adopt

“Next Generation” inorganics for ferrous

and steel no-bake applications to

overcome the disadvantages with traditional

sodium silicate binders. For

the United States, looking to the EU is a

good indicator of what sorts of technology

should be considered and what regulations

may be headed Stateside.

As suppliers, we too have a role to

play. Our organizations need to see

compliance with emission standards

as reality, and to use sustainable development

to drive innovation; to look

for both revolutionary and continued

evolutionary development of products

and processes, so that the future for

foundries in the EU and the U.S. will

be as good as we think it can be.

What drives innovation in the

metalcasting industry?

The theme of this paper is to compare

the EU and U.S. foundry industries

as it pertains to molding methods

and materials. Information presented

has been gathered through published

data and personal interviews, email

exchanges and conversations with experienced

colleagues and metalcasting

experts to give the material greater

depth and relevance.

The key question we are trying to

answer is what drives innovation in

the metalcasting industry? In particular,

as it pertains to molding materials

and the differences between primarily

western Europe and the United States.

And in which direction? Is technology

coming East to West, or does it go from

the U.S. to the EU?

For many years, the typical drivers of

innovation have been the four “P” Peaople,

Processes, Productivity and Profit.

If you add “Planet” to the Equation, you

get something very familiar — Sustain-

Casting Plant & Technology 4/2016 37


K MARKETS

ability. “Advanced Sustainable Foundry1”

was the theme for the 71st World

Foundry Congress held May, 2014 in

Bilbao. At the Congress, Dana Cooper

gave a compelling speech indicating

that Sustainability is now the key driver

of innovation. Dana stated that foundry

companies have moved past the fear

that “sustainable” and “environmentally-friendly”

equates with being less

competitive in the marketplace and

that it adds cost, and reduces profit.

In fact, we are seeing design constraints

being imposed on many product

offerings – binders, coatings and

other consumables – by regulations

that are moving us to conserve resources,

save energy and reduce emissions. It

is clear, both in the EU and the United

States that emissions standards are and

will continue to be the key driver behind

product and process innova-tions.

General metalcasting comparisons

There has been a worldwide increase

in foundry capacity over the last ten

years. From the latest published data

[2], global metalcasting is on track to

reach at least 110 million tons by 2015

(Table 1).

In 2013, global production increased

to more than 103 million metric tons,

an increase of over 3% when compared

to the previous year, according to Modern

Casting. The top 10 nations produced

88 % of the world’s castings, a

figure that remains unchanged from

2012 as does the relative positions

of the top 10 producing countries

(Table 2).

In the EU, production was mostly

down in 2013. France, Germany reported

3 % to 5 % decreases. An exception

was Poland. Meanwhile, the United

States, the world’s second largest producer,

saw its tonnage increase by nearly

4 % to 12.25 million metric tons. Also,

from the published article, the U.S. saw a

4.4 % increase in its productivity per site,

with its 2,001 metalcasting facilities averaging

6,122 metric tons. Germany, the

world leader in per plant production at

8,659 metric tons per plant, remains the

world’s leader in productivity per plant.

China increased its total production

by two million metric tons to a total of

44.5 million. That boost represents a

large majority of the overall increase in

global production, meaning China continues

to increase its share of the global

market. It is recognized that the over the

past ten to fifteen years, there has been a

shift of metalcasting production capacity

to Asia, to what Don Huizenga [3],

former foundry owner, and a past president

of both the American Foundry Society

and the World Foundry Organization,

called the “Tier 1”; namely, China,

India and South Korea. In 2013, China,

India & South Korea make up over 55 %

of the world’s metalcasting production.

The West (including the EU and US)

has lost significant capacity over the

last 20 years to the East. The U.S. has

decreased from a market share of about

20% to about 10%, while China has increased

from 15% to over 40% in that

timeframe. In the last five years alone,

China has shown over 30% growth in

market share. The U.S. metalcasting industry

has faced the closing of thousands

of plants during this capacity migration.

This shift of capacity has affected both

the EU and the United States.

The U.S. metalcasting industry is

made up of 1,965 facilities (most recent

data), down from 2,170 five years

ago. This reduction can be attributed

to the 2008-2009 recession, technological

advancements, foreign competition

and tightening regulations. Industry

capacity is 15.5 million tons,

with the industry forecast to operate

at 81 % of capacity in 2015.

Taken as a whole, the EU is the world’s

second largest metalcasting producer,

producing some 15.2 million tons vs.

the U.S. at 12.25 million tons [4]. The

EU has almost 2.5 times as many casting

plants as the United States, some

4,958 plants vs. the U.S. at roughly

2,001 based on 2013 data. However, if

you look at the NAFTA region by adding

Canada and Mexico, casting production

is 15.1 MM tons, pretty much

at parity with the EU, but still the EU

has almost twice as many plants.

Jahr

Quantity in

million tons

2004 79.745

2008 93.449

2010 91.673

2012 98.269

2013 103.20

2015

110.00

(Forecast)

Table 1: Global foundry production

Future forecast: Risks and opportunities

Let’s look at the future forecast. For the

EU, the forecast is cautiously optimistic.

Much depends on GDP and monetary

and other political issues. Most

view the recent decline in the value of

the Euro should be good for growth, as

exports make up a huge chunk of Europe’s

GDP, more than a quarter [5].

Heiko Lickfett from the German

Foundry Association predicted at last

year’s IFF in Venice forecasts that Western

Europe can hold level with slight

increases in iron, steel and aluminum

[4]. The CAEF sees Western Europe

with increases around 4% from 2015-

2018 in iron and steel, and a more bullish

forecast for aluminum over the

same three year period of nearly 8%.

Eastern Europe is more dynamic with

potential for even higher growth rates.

There are some concerns. In Germany,

electric energy costs have risen

over 40 % for the 4 year period 2007

2016. For Italy, the 9th largest casting

producer and leading non-ferrous

producer in the EU, there are real headwinds

ahead. Energy costs are 30 %

higher compared to its European partners.

For the EU, most of the growth

coming from exports of castings may

be displaced as investments in casting

production in regions such as NAFTA

and China are mainly based on investments

of European OEMs [4].

Germany remains at 5th in overall

casting production and is the largest

single country in the EU in terms of

metalcasting production; therefore,

most of the following comparisons will

focus on Germany as compared to the

United States (Table 3).

German foundries: highly productive

What drives the high productivity in

German foundries? In personal conversations

and interviews with a num-

38 Casting Plant & Technology 4/2016


Country

Casting production in Number of foundries

million tons

China 44.5 30 000

U.S. 12.25 2001

India 9.81 4600

Japan 5.54 2085

Germany 5.18 599

Russia 4.1 1200

Brazil 3.07 1352

Korea 2.56 910

Table 2: Top 10 countries in casting production (Source: 48th Census of World

Casting Production)

Germany

USA

Position among the top ten 5 2

Produktivity very high high

Labour market Need for more specialists Need for more specialists

Energy costs high low

Capacity utilization fully occupied capacity utilization of 75-80 %

Table 3: Germany and the USA in comparison

ber of individuals familiar with both

markets, all stated that innovation is

what drives productivity in Germany.

Their view, shared by many, is German

foundries employ more advanced use

of technology and automation; German

foundries tend to be more modern,

better capitalized, well-maintained

and well-managed. Their senior

management and leadership staffs

have more engineering backgrounds

versus the predominant production

& financial backgrounds found in U.S.

foundries.

Additional qualitative differences include

more focus on process and metallurgical

control during manufacturing

and less on inspection and quality

control after casting. The low energy

costs of the United States should not

be ignored. It is a key advantage U.S.

foundries have over their EU counterparts.

In fact, according to author Peter

Zeihan, the United States is looking at

decades of low natural gas prices, primarily

due to the shale gas boom, horizontal

drilling and hydraulic fracturing

techniques [7]. He goes on to state

that since 2008, U.S. average electricity

prices are now the cheapest in the

world. Quite an advantage for an energy

intensive industry such as metalcasting.

Molding material differences

Let’s take a closer look at differences

between the EU and U.S. in molding

materials usage and choices and how

regulations drive those material choices.

We will examine differences in several

areas:

» Differences between EU and U.S.

foundries from a product technology

perspective

» Differences between product development

strategies of major suppliers

» Differences between EU and U.S.

foundries from environmental regulations

Figure 1 compares foundry binder usage

[8] in the EU and the US. There are

two key differences. First, is the greater

use of the Furan No-Bake (FNB) process

(shown here as Acid Cured binders,

which includes a small amount

of Phenolic No-Bake) in the EU, especially

in Germany. Over twice as much

FNB is used in the EU (44 %) as in the

US (19 %). On the other hand, the use

of Phenolic Urethane No-Bake predominates

in the United States (nearly

25 % in the US vs. only 3 % in EU—

over 8 times as much!). In fact, there

is virtually no PUNB used in Germany.

Why the difference? One reason is

historical. Furan No-Bake binders were

developed in the late 1950s ten years

earlier than Phenolic Urethane binders.

FNBs depend upon a key raw material,

furfuryl alcohol that is derived

from agricultural by-products such

as corn cobs and sugar cane bagasse.

Periodic shortages of these materials

due to fluctuations in crop harvests

can reduce supply and drive up prices.

In response to these unpredictable

variations, phenolic urethanes were

developed in the United States by the

Foundry Division of Ashland Chemical

in the late 1960s and introduced

to the foundry market in the U.S. in

the early 1970s (in the case of Phenolic

Urethane Cold-Box as a response to

high natural gas prices due to the first

oil embargo). U.S. foundries had the

initial access to this technology earlier

than those in the EU, and converted

to the new technology. The conclusion

is material choices tend to be regional

versus a single global market driver.

Today, there is overwhelming use of

Furan No-Bake binders (FNB) as the

system of choice for EU steel foundries.

This contrasts quite differently from

the U.S. where Phenolic Urethane No-

Bake binders (PUNB) are the predominant

choice for steel foundries [9].

Product solutions tend to be more

company specific than regional. That

is, one company’s solution to continuous

product improvement and to meet

environmental regulations may not be

the same as the next.

For example, for nearly fifteen years,

Hüttenes-Albertus, Düsseldorf, Germany,

has used tetraethyl silicate (TEOS)

a hybrid inorganic/organic material,

to reduce emissions, smoke & odor in

urethane cold-box (PUCB) systems. For

the past three years, HA International

has used this same technology in urethane

no-bake (PUNB). Other suppliers

have chosen a different route using

conventional aromatic solvents with

improved environmental characteristics

to achieve similar results.

While beyond the scope of this document

to analyze which approach is

Casting Plant & Technology 4/2016 39


K MARKETS

“better”, such dichotomy gives foundry

customers a choice to maintain

compliance with regulations and to

enhance productivity and profit.

Those are examples of continuous

evolutionary development with incremental

advantages. The introduction

of the new generation of inorganic

binders over the last five years

represent an ex-ample of revolutionary

technology—and an example of radical

thinking in product innovation.

It is also another example of a regional

trend. The usage of “Next Generation”

inorganic binders has been

led by Germany and a few other EU

countries, who adopted these binders

for high production of automotive aluminum

cast parts earlier than the United

States.

For over ten years, the EU has had

keen interest in inorganic binders,

primarily due to more stringent environmental

regulations for air emissions,

water contamination and odor.

In November, 2002, this was brought

into sharp focus after a VDG Conference

titled, “Inorganic Binders – breakthrough

or everlasting hope?” and especially

after the 2003 GIFA when

legacy Laempe introduced the “Beach

Box” process.

Now, German OEM and Tier 1 automotive

foundries are using inorganic

binders in high volume aluminum

casting applications; namely,

VW, Daimler, BMW, Nemak, Martinrea

Honsel and a few others. While still

being introduced at several of these

high profile foundries, reclamation

of these advanced inorganic binders

works, usually a combination of both

mechanical and thermal treatments.

As German OEM and Tier 1 automotive

foundries build new facilities in

other regions of the world, China, Mexico

and others, they are taking inorganic

with them. This in turn has started an

interest in testing and evaluating these

systems by OEMs in Japan and Korea.

But not so far in the United States.

While some Asian OEM transplants in

the U.S. are evaluating advanced inorganics,

the progress is slow. The focus,

at least at this point in time appears to

be more on improving productivity of

organic systems. Why the difference?

32 %

3 %

Acid Cured Phenolic Esters PUNB PUCB

Hot-Box

2 % 3 % 1 % 1 %

14 %

Shell

EU

inorganic

44 %

Others

Binder companies providing this

technology have noted that it takes significant

organizational commitment

to get inorganics running, both from

the supplier and the customer. The “innovators”

and “early adopters” have all

made multiple year commitments to

get inorganic commercialized in serial

applications. That commitment also

involves significant equipment investment

and process change.

Consider that each binder system

has its own performance and process

characteristics:

» binder system chemistry

» sand preparation requirements

» strength development characteristics

» system productivity

» pattern and tooling requirements

» mixed sand flowability and blowability

» ease of sand removal and shake-out

» sand reuse levels and reclamation requirements

» cost per ton of mixed sand

37 %

2 %

5 %

2 %

Figure 1: Comparison of foundry binder usage in the EU and the US (Graphics: HA)

USA

2 %

19 %

25 %

8 %

Some binder conversions such as Phenolic

Urethane Cold-Box (PUCB) and

resin coated sands (RCS) to inorganics

involve large changes in these characteristics.

The goal in any of these

changes is to maintain productivity,

sand reuse levels, casting quality and

of course, costs. For smaller metalcasting

facilities the investment cost versus

the benefit is huge.

Nor can the difference be explained

by differences in aluminum engine applications.

Most cylinder heads in U.S.

light truck and passenger cars are aluminum.

Aluminum is also used for motor

blocks, although some larger displacement

blocks remain in cast iron.

Aluminum production in the U.S. is

over 1.68 million metric tons – albeit

not all automotive – nearly twice as

much as Germany [2].

And, there are always exceptions.

One such exception in the United States

is the use of inorganic chemistry in ablation

casting. Honda recently unveiled

the production version of its Acura NSX

sports car, which uses advanced materials

and production processes in building

the car. In an article in the April

2015 Modern Casting issue, key to the

design were three cast aluminum connecting

joints produced by Honda via

the ablation casting process [10].

Ablation casting provides the same

metallurgical properties as the surrounding

aluminum extrusions, previously

unattainable in a casting alloy.

Shannon Wetzel, author of the

article goes on to say, “Honda was

able to achieve the necessary properties

and design requirements with

ablation casting by partnering with

Alotech Limited, Cleveland, Ohio. Ab-

40 Casting Plant & Technology 4/2016


lation casting is a new technology invented

by Alotech that combines the

flexibility of traditional sand casting

techniques with rapid cooling of the

molten alloy through the use of a water-soluble

(i.e. inorganic) binder” [10].

The casting was selected as “Casting of

the Year” at the recent AFS Metalcasting

Congress in April 2015. The Alotech

ablation casting process is intriguing to

see in action and an example of American

innovation and entrepreneurship.

Environmental Regulations

In terms of environmental regulations

[11, 12] and its impact on molding

and core making systems, there are

some areas where the EU lags and some

where it leads. One “lag” is in the classification

of formaldehyde, which can

be a constituent of many foundry resins,

including Furan and Phenolic No-

Bake resins and Phenolic Urethanes,

both Cold-box and No-bake resins.

In the EU, formaldehyde has now

been classified as a Category 1B carcinogen

from a Category 2B. Category

2B means formaldehyde is a suspected

carcinogen; Category 1B is presumed

to have carcinogenic potential for humans.

The classification is largely based

on animal evidence. This change was

to be effective April 2015 but has now

been deferred until January 1, 2016.

It will force all resins containing

formaldehyde to “non-reportable”

formaldehyde levels (< 0.1 %), meaning

that warnings do not have to appear

on labels and Safety Data Sheets

if levels are below 0.1 %.

In the U.S., formaldehyde is classified

as Category 1A carcinogen,

meaning it is known to have carcinogenic

potential for humans. The classification

is largely based on human

evidence. But, US EPA’s regulation of

formaldehyde as a known human carcinogen

is controversial. EPA reversed

it prior stance several years ago and

changed the manner in which they

assessed the carcinogenic potential of

formaldehyde in humans.

It is interesting to note that the EU

reviewed the same data as US EPA at approximately

the same time and came

to a different conclusion regarding the

carcinogenic potential.

In the United States, formaldehyde

was more tightly regulated by OSHA

in the mid-1990s (CFR 1910.1048) and

driven by worker exposure concerns.

So, foundries and binder suppliers

have years ago addressed this concern.

Foundry resins are already formulated

to < 0.1% in most binder segments.

REACH vs. TSCA [11, 12]

REACH is the Regulation on Registration,

Evaluation, Authorization and

Restriction of Chemicals. It entered

into force on June 1, 2007. TSCA is the

Toxic Substances Control Act of 1976.

It provides US EPA with authority to

require reporting, recordkeeping and

testing requirements, and restrictions

relating to chemical substances and/or

mixtures. The main difference is that

in the EU, REACH generally requires

chemical producers or importers to

demonstrate a product is safe – “no

data, no market”. Testing and documentation

is required. Under TSCA,

EPA has the burden of demonstrating

a product, or chemical is not safe; testing

is not normally required by companies.

TSCA reform in the United States is

currently under legislative debate and

subject to possible regulatory change.

Future Trends

There are several trends in the casting

industry getting equal interest on

both sides of the Atlantic Ocean and

reported by both Lickfett [4] and Modern

Casting [10].

» Substitution: Efforts continue in

substituting cast parts for weldments

» Additive Manufacturing: Use of 3-D

printing of cores and molds; Potential

threat of direct printing of metal

A brief look in the April 2015 issue of

Modern Casting, shows many examples

that demonstrate the ability of

castings to substitute for other competing

materials and forming processes

and do so in a manner that saves the

end user time and money.

3-D printing is often described as a

“disruptive technology” and according

to many sources is continuing to

expand at a rapid rate with expected

growth of 30 % annually.

According to Nicholas Leider, Associate

Editor of Modern Casting, “Metalcasters

have already seen the impact of

3-D printing and are using it in the production

of patterns and for sand cores

and molds – a process that can take weeks

off lead times and reduce costs related to

product development. 3-D printing of

metal has lagged behind other methods

materials, but recent advancements have

led to the technology being used for prototyping

and small-run production parts

[14].” The process has gained interest in

a wide variety of important adopting industries,

such as aerospace, automotive,

engineering and medical.

3-D printing of metal is a technology

that could impact the metalcasting

industry, but not necessarily negatively.

It could impact metalcasters

in positive ways. Nicholas Leider goes

on to say, “Processes may develop into

potential sources for tooling and dies.

Direct metal printing also may become

another viable option for rapid prototyping

and small run components, becoming

a new resource for metalcasters

[14].” 3-D printing of sand cores and

molds is gaining acceptance, especially

as printing speeds improve. Which

according to a recent Additive Manufacturing

Workshop held concurrently

with the American Foundry Society

Metalcasting Congress in Columbus,

Ohio, USA, is exactly what 3-D printing

companies are planning to do.

It is clear that environmental regulations

will get more stringent. Most

people have already heard about Emissions

Trading, also known as “Cap and

Trade”. The efforts to reduce global carbon

emissions are one with which everybody

can agree. In 2013, a record 36

billion t of CO 2

was released from all

sources. The biggest emitters were China,

which produced 29 % of the total,

followed by the U.S. at 15 %, the EU at

10 % and India at 7.1 % [15].

While not the only greenhouse gas

of concern, carbon dioxide represents

over 60 % of all greenhouse gasses and

is generally used as the bellwether. The

drive for reducing emissions from all

foundry sources should be clear.

References:

www.cpt-international.com

Casting Plant & Technology 4/2016 41


A vehicle in the Mercedes BR222 series (S-Class) illustrated with rear suspension strut dome in position (Photo: Daimler AG)

Author: Klaus Vollrath, Aarwangen, Switzerland

Aluminum structural castings:

greater capacity for Europe’s

premium cars

Hybrid car body structures made of steel and aluminum have become established at Europe’s

premium producers. Considerable weight savings, and thus reduced fuel consumption, can be

achieved with such constructions. DGS Druckguss Systeme AG, based in St. Gallen in Switzerland,

proves its competence as a development partner for the worldwide large-scale production

of such castings by delivering large-format structural components for the hybrid body of Mercedes’

new C-Class. The next step is to build up production and logistical structures that meet

the needs of Europe’s premium producers throughout the market – not only regarding development

competence and component quality, but also production capacities and cost structures

“The successful collaboration with Mercedes

in developing aluminum structural

castings for the hybrid body of Mercedes’

new C-Class was an important

breakthrough for us,” says a pleased

Axel Schmidt, Manager of Technology

and Sales at DGS Druckguss Systeme

AG. The company was thus able to prove

that they met all the prerequisites for

supplying premium producers not only

for niche vehicles, but also for models

that are mass-produced worldwide. This

also involved mastering the appropriate

technology so well that a smooth worldwide

supply of the necessary parts could

be assured. DGS can supply three of the

four works in which Mercedes produces

the C-Class: the parts for Germany and

South Africa come from the DGS works

in Switzerland, supply of the Mercedes

works in China takes place via the DGS

foundry in Nansha (China), which was

appropriately qualified by personnel

from St. Gallen. And the local casters responsible

for production in America received

technological support from DGS

specialists.

42 Casting Plant & Technology 4/2016


For the specialists from Switzerland,

the successful technology transfer was

both a challenge and an accolade for a

different, higher, level of qualification.

Strategies and training procedures had

to be worked out at the various sites,

which previously had no experience

with such structural castings. The setting

up and implementation of serial

production abroad was possibly the

greatest challenge in this project – due

to variations in the level of technological

mastery, language barriers and differences

in mentality. “We at DGS are

particularly proud that we were the

first European casters to take on this

enormous challenge and positively

master it,” Axel Schmidt said after the

successful start of production.

A step into the extensive European

premium market

“Even then it was clear to us that in

future we would have to face rapidly

growing demand for such parts for

other models and carmakers, too,” adds

Schmidt. This was easy to see from the

large number of inquiries and development

projects DGS was involved in.

Apart from Mercedes, the company was

also in discussions with other premium

producers such as Audi, Porsche and

BMW. It was obvious that the emerging

demand already present just in Europe

would be impossible to cover with the

capacities available in St. Gallen, while

the lack of available space ruled out any

major expansion. Completely rebuilding

the company on a sufficiently large

piece of land was also out of the question

for another reason: the very strong

Swiss franc at the time had become a

serious and, in some cases, even insurmountable

handicap – above all for vehicles

in the medium to lower price

segments. It was therefore necessary to

find ways to carry out some of the corresponding

production abroad, where

there was a more favorable costs situation.

A condition and requirement for

this, however, would be transferring

the familiar high quality of the Swiss to

whatever country was selected. In this

situation, DGS decided to become the

first European die-casting foundry to

set up production of large-format structural

castings in the Czech Republic.

The works in Liberec (the

Czech Republic)

“This made it possible for us to participate

with our efficient modern aluminum

die-casting foundry,” reveals Luboš Pfohl,

Managing Director of DGS Druckguss Systeme

s.r.o. in Liberec in the Czech Republic.

Since the 1990s, numerous companies

involved in plastic processing, machine

construction and the automotive supply

industry, in particular, have settled in this

highly dynamic industrial region south

of the border triangle made up of Germany,

Poland and the Czech Republic. The

die-casting foundry was built as a proverbial

‘garage startup’ in 1990 during the

economic liberalization, and was quickly

able to gain a good reputation, particularly

in the country’s growing automotive

industry. Economic crises and the

DGS made the leap into large-scale

production with the development

partnership for castings such as this

suspension strut dome for the Mercedes

C-Class

desire to grow, also westwards, provided

an impetus for collaboration with a western

partner. Consequently, the takeover

by what is now DGS took place at about

the turn of the millennium. Since then,

the rapidly growing works in Liberec has

developed into one of the most important

suppliers for European carmakers, delivering

high-quality ready-to-install castings

exactly to specification and within

deadlines – meeting the requirements of

this very demanding market. Systematic

preparation for the production of structural

castings had already begun in 2014

with intensive support from the parent

company in St. Gallen. For this purpose,

The production of structural castings for the S-Class and GLC models from Mercedes now takes place on three modern

Carat die-casting cells at the Liberec works

Casting Plant & Technology 4/2016 43


K COMPANY

three modern, fully automated Carat

die-casting cells from Bühler, Uzwil, Switzerland,

with clamping forces of 1,300

tonnes and 1,600 tonnes, as well as the

necessary upstream and downstream logistical

chain – from the separate incoming

metals store with its own spectral analysis

system, through heat treatment and

processing equipment, to dressing and inspection

stations – were setup and audited.

Parallel to this, the employees received

appropriate training, and the processes in

the company were structured in line with

the new needs. Serial production of structural

castings for the Mercedes S-Class and

its GLC models started in mid-2015. In

the meantime, the development of parts

for other vehicles from Porsche, Audi and

VW has already advanced to the samples

phase in some cases.

Double strategy for optimum

Europe-wide logistics for structural

castings

“Thanks to this strategy, the two DGS

works now act as a team for their European

customers with different, but coordinated,

performance profiles – and can

therefore cover an extraordinarily wide

product range,” explains Schmidt. Each

of the sites has its specific advantages. In

St. Gallen, DGS has a recognized high

level of expertise in the development

and production of large-format structural

castings that has made the site a

sought-after partner for joint projects in

the further development of such applications.

In addition, the company has

particularly large die-casting cells with

clamping forces of up to 3,200 tonnes

here. The works therefore also remains

indispensable for its function as a development

site, as well as a production site

for particularly demanding large-format

structural castings. On the other hand,

the works in Liberec is continuously improving

its level of competence thanks

to constant transfers of technology and

expertise, and can thus also serve other

market segments. The procurement

of another Bühler Carat 160 plant is already

planned for autumn 2016.

Massive capacity expansion in

the Czech Republic

“In view of the enormous interest in

our products we will steadily expand

A ‘marshalling yard’: the castings are passed through a fully automatic furnace

plant to achieve the desired properties

the Liberec site during coming years,”

Pfohl reveals. As the existing buildings

are already fully occupied, several new

halls will be constructed on an area of

the works grounds that has not already

been built on. Up to eight new Carat

plants with clamping forces of up to

2,500 tonnes – and all the associated

upstream and downstream equipment

such as the melting shop, heat treatment,

processing centers and surface

treatment – will gradually be installed

here during the coming years. Because

the company has been able to make

plans for this land without being bothered

by existing structures the other infrastructure

can be designed to meet

state-of-the-art requirements in terms

of works planning and workflow management.

Another building providing

a separate energy supply, as well as one

that will house an office and personnel

section, are also planned. “This expansion

will equip us to meet all expected

upcoming market needs in the coming

years,” stresses Pfohl. According to current

planning, production in the new

works is expected to start in late 2018/

early 2019.

www.dgs-druckguss.com

Maximum care is taken during final

inspection of this processed suspension

strut dome for the Mercedes

GLC (BR 253)

44 Casting Plant & Technology 4/2016


OTTO JUNKER

Groundbreaking ceremony at Otto Junker’s Lammersdorf site, attended

amongst others by Marcel Philipp, Lord Mayor of Aachen (4th from left), and

Dr. Ambros Schindler, Member of the Board of the Otto Junker Foundation

(4th from right)

Expanding production, securing

employment

Two new production buildings are to

be erected at Otto Junker’s Lammersdorf

site with a view to safeguarding

the company’s future competitive

strength in global markets. The shops

will accommodate the central optimization

of coils, one of the key components

of coreless induction furnaces,

as well as their fabrication in line

with market demands. Construction is

scheduled to be completed in the second

half of 2017. The new sheds will

add another 3,440 m² to Otto Junker’s

current 30,300 m² of manufacturing

floorspace. Otto Junker is to invest approx.

4 million euros in the new shop

buildings, thus securing existing employment

and creating the basis for

new jobs. Another 1.5 million euros

will go towards the erection of a new

employee welfare building and new

foundry equipment.

For the symbolic ground-breaking

ceremony marking the start of construction

of the new production buildings

at 12:00 noon on August 18, 2016,

the management of Otto Junker GmbH

had invited all parties involved in the

project, regional community leaders,

as well as journalists from the local

press and technical trade press.

Markus D. Werner, Chairman of the

Managing Board of Otto Junker GmbH,

welcomed all guests on behalf of the

Otto Junker Foundation, the Supervisory

Board, and the Managing Board of

Otto Junker GmbH. By inviting the attendees

to witness the turning of the

first sod for the new buildings, he emphasized

his confidence in the future of

the site and, more specifically, of Otto

Junker GmbH. “Our aim is to secure

growth and to create the basis for new

jobs with this investment”, he said.

Along with Bernd Goffart, Vice-Mayor

of the Municipality of Simmerath,

Werner welcomed further invitees including

Helmut Brandt, member of the

German parliament, Mr. Stefan Kämmerling,

member of the provincial parliament

of North Rhine-Westphalia,

Mr. Marcel Philipp, Lord Mayor of

Aachen, and Franz-Josef Hammelstein,

chief of the Lammersdorf community.

Werner expressed special thanks to the

planning team and to all other parties

involved in the project who had given

their support in the last few months

and would continue to do so in the

months to come to see the construction

project through to its successful

completion, thus expanding the

available surface area for the projected

purpose, i.e., for the future coil fabrication.

Before Werner gave the floor to

Helmut Brandt, a brief welcoming address

to the entire audience was delivered

by Mr. Markus Kroner, spokesman

for the Goldbeck general contracting

firm. Next on the speakers list were Stefan

Kämmerling, Marcel Philipp, Bernd

Goffart und Franz-Josef Hammelstein.

The highlight of the event, needless

to say, was the symbolic turning

of the first sod. This was followed by

Werner’s invitation for a snack lunch

at the teahouse in Junker Park which

was still built by the company’s founder,

Mr. Otto Junker.

www.otto-junker.de

ATLAS COPCO

Acquisition of Leybold Vacuum

completed

Atlas Copco, Stockholm, Sweden, a

leading provider of sustainable productivity

solutions, owns the former Oerlikon

Leybold Vacuum GmbH, renamed

Leybold GmbH. Founded in 1873, Atlas

Copco is a global player with more than

43,000 employees in over 180 countries.

Leybold becomes part of the Vacuum

Solutions Division, belonging to the

Compressor Technique Business Area,

with approximately 6,500 employees

represented in over 35 countries.

With this acquisition, Atlas Copco

trusts the strengths of the vacuum specialists

at Leybold, founded in 1850,

who will keep their traditional and

well-known brand in the market.

“The technological know-how and the

innovative spirit of Leybold will complement

our vacuum portfolio and

strengthen our market presence, contributing

to our customers’ success,”

says Geert Follens, President of the Atlas

Copco Vacuum Solutions Division.

Leybold, headquartered in Cologne, Germany,

and has a 166-year long history,

develops and delivers vacuum pumps,

systems, standardized and customized

Casting Plant & Technology 4/2016 45


K NEWS

vacuum solutions and services for various

industries. As a leading supplier of

vacuum technology, Leybold offers sustainable

solutions for industrial processes

such as secondary metallurgy and a range

of coating technologies. With a high application

expertise in the fields of analytical

instruments, display production

as well as in research and development,

Leybold ranks among the world’s top providers

and has always been a part of wellknown,

globally active companies.

With rough, medium, high and ultra-high

vacuum pumps, vacuum systems,

vacuum gauges, leak detectors,

components and valves, as well as

consulting and engineering of turnkey

vacuum solutions, Leybold provides

a very broad portfolio for general

and specific customer applications.

“We will continue to support our customers

in the future with our vacuum

expertise.

Our enhanced product portfolio,

sustainable after-sales services and

proximity to our customer will distinguish

us as a reliable business partner”,

says Steffen Saur, Chief Marketing Officer,

responsible for the global sales

and service activities of Leybold. “Additionally,

by combining Atlas Copco’s

and Leybold’s strengths in industrial

dry pumps and scientific turbo pumps,

it will provide a technology platform

for superior next generation products.”

As a pioneer of vacuum technology,

Leybold will continue to focus on performance

and growth in the industrial,

research and development, and analytical

market sectors.

www.leybold.com

GEORG FISCHER AUTOMOTIVE

Automotive foundry secures

major order for hybrid vehicle

components

GF Automotive, a division of GF,

Schaffhausen, Switzerland, has received

an important order from a

French car manufacturer for the battery

housing of a new hybrid vehicle.

The contract for this new customer

amounts to 77 million euros.

The battery housings made of aluminum

with an integrated cooling system

will be produced in Germany as of

2019. This recent major order underscores

the development and manufacturing

skills of GF Automotive in the

growing market for E-mobility. With

an eye to maximizing the vehicle’s

range, the lightweight design is a particularly

important factor.

GF Automotive is one of the world’s

leading automotive suppliers and a

technologically pioneering development

partner and manufacturer for

components of passenger cars, trucks

and industrial applications. Each

year the division manufactures some

600,000 tons of iron, aluminum and

magnesium at eleven production plants

in Germany, Austria, China and the US.

GF comprises three divisions GF Piping

Systems, GF Automotive, and GF Machining

Solutions. GF Automotive with

headquarter in Schaffhausen is a recognized

development and serial production

partner of the automotive industry

and industrial applications with 11

production sites in four countries (Germany,

Austria, China, USA). The core

business is the development and production

of highly stressable castings in

iron, aluminum and magnesium. GF

Automotive has therefore designed the

Example of a battery housing

(Photo: GF Automotive)

research & development for years on

weight reduction and lightweight and

the reduction of CO 2

emissions and efficient

fuel consumption.

www.gfau.com

ENEMAC

Clamping – robust and reliable

The hydromechanical spring clamping

cylinder ESZS of Enemac, Kleinwallstadt,

Germany, is manufactured

in 9 sizes and includes a nominal

clamping force range of 16 kN up to

350 kN.

Since the clamping force is built up

mechanically by pre-loaded disc spring

package – the hydraulic system is only

required for the release stroke of the

elements – this system ensures reliable

high operational safety, as the clamping

force is maintained independently

of oil pressure or leakage losses.

Cost saving, the ESZS can be used

anywhere where sliding or moving

parts need to be fixed or clamped.

Equally it can be used for jigmaking or

mold and die clamping.

www.enemac.de/en

The ESZS can be used anywhere

where sliding or moving parts need to

be fixed or clamped (Photo: Enemac)

46 Casting Plant & Technology 4 / 2016


TRIMET

Increased capacity for high-quality aluminum

foundry alloys

Trimet Aluminium SE, Essen, Germany, has reacted to the

growing demand for high-quality foundry alloys by investing

in a second horizontal continuous casting plant at its Essen

works. Hertwich Engineering, Braunau am Inn, Austria, a

subsidiary of the SMS group (www.sms-group.com), has been

selected as equipment supplier.

Horizontal casting units have been part of Hertwich’s product

range for 40 years. During that time the company has been

able to accumulate comprehensive experience from numerous

projects. That experience has contributed toward a continuous

process of improvement, which has brought the company

to a technological peak in this sector. In fact, the use of

such plants is in no way limited to foundry alloys, as described

below.

Trimet supplies foundry alloys optionally in the form of bipart

ingots of a belt-type ingot caster or as horizontal continuously

cast ingots. For ingot production, in 2013 a belt-type

ingot caster for 30,000 tons per year went into operation. The

existing horizontal continuous casting line with a capacity of

40,000 tons per year, which has been in operation since 2003,

has now been supplemented by a second line for 60,000 tons

per year. Thus, at the smelter casthouse in Essen horizontal

continuous casting currently accounts for around a third of

the production capacity. Both horizontal casting units and

the belt-type ingot caster have been supplied by Hertwich.

Horizontally cast ingots are preferred as demanding input

stock for direct processing. The market development shows,

that aluminum for highly stressed castings, such as those used

in particular by the automotive industry, is increasingly requested.

In fact, Trimet confirms that the output of the new

casting plant is destined for the automotive industry.

Important aspects are the economical plant operation and the

quality of the products. The quality-relevant advantages of continuously

cast alloys are: low contents of hydrogen and oxide as

well as non-metallic inclusions, fine-grained and uniform microstructure,

uniform distribution of the alloying elements, no

segregation due to gravitational effects, free from cracks, cavities

and inclusions, great uniformity in the dimensions, straightness

and weight of sections cut from the strand and smooth surface,

which simplifies stacking, strapping and also dispatch.

In consideration of economic aspects automation, output

and availability of the plant play an important role. The horizontal

continuous caster is designed for 32 strands of 90 mm

x 54 mm. The height of the strands is different from the generally

established standard dimension of 75 mm. The larger

strand cross-section benefits a higher casting rate.

Stacking, marking, strapping and weighing are integrated

in the automated process using well-proven standard components.

For stacking, Hertwich uses an industrial robot

which, on the one hand, has the necessary degrees of freedom

of movement but which is, at the same time, also designed

for high accelerations or decelerations.

Automatic strapping of the pile loops (Photo: Trimet)

Besides monitoring the operation, the control system is

also responsible for managing the administrative data and

for documenting all operating parameters. Each individual

working step is checked by special monitoring and diagnosis

programs. In the event of deviations, the control system

reacts immediately.

www.trimet.eu/en

Casting Plant & Technology 4/2016 47


K BROCHURES

Equipment for aluminium production

16 pages, English

A brochure covering the solutions and products offered by Seven Refractories for

the aluminium industry. It provides detailed and clearly structured information as to

the types of refractories to be used in different furnaces and in the various furnace

zones.

Information: www.seven-refractories.com

Machines and equipment for moulding sand preparation

20 pages, English

This brochure presents the Eirich mixing system, technical features of the mixers and

advantages of the technology. The range of mixing equipment offered by Eirich

includes individual mixing units and a wide range of systems for integrated and

modular solutions with state-of-the-art process control.

Information: www.eirich.com

Automatic moisture control

4 pages, English

A brochure providing information on automatic moisture control at the batch mixer

with sensor technology from Sensor Control. Examples of automatic water dosing

systems, installation possibilities for moisture measuring probes and explanations

about the measuring process are provided.

Information: www.sensor-control.de

Optical emission spectrometer

4 pages, English

This brochure features the Q4 Tasman advanced CCD-based optical emission spectrometer

offered by Bruker. It sets out technical data of the different instrument

models, the available analytical solution packages, electrical data, weights and

dimensions, etc.

Information: www.bruker-elemental.com

48 Casting Plant & Technology 4/2016


Investment castings in no-bake sand

6 pages, English

This brochure provides an overview of equipment offered by Küttner for investment

casting processes in no-bake sand. The equipment ranges from sand mixing,

shaking-out and reclaiming equipment for a full cycle at one stop to fully automatic

crane systems and complete systems even for large investment castings.

Information: www.kuettner.com

Furnace lining systems

12 pages, English

A brochure providing an overview of Foseco’s extensive portfolio of monolithic and

precast refractory solutions for long-campaign cupola melting, coreless induction

melting, channel holding and pouring furnaces in iron and steel foundries as well as

various ancillary products.

Information: www.foseco.com

Melting, holding and heating solutions for aluminium

8 pages, English

A brochure setting out process line solutions in aluminium casting provided by

Andritz. Featured in this brochure are furnaces for melting and holding as well as

pusher-type furnaces and pit and car bottom furnaces for heating and homogenizing.

The furnaces are designed for minimum energy consumption.

Information: www.andritz.com

Management consulting

24 pages, English

A company brochure setting out the services offered by KW Consulting Group, an

independent, industry-focused consulting company. The services include singlesource

management requirement solutions for mid-size foundries as well as for

national and international metal industry companies.

Information: www.kwcg.de

Casting Plant & Technology 4/2016 49


K INTERNATIONAL FAIRS AND CONGRESSES

Fairs and Congresses

13th Edition of IFEX – International Foundry Exhibition

February, 3-5, 2017, Kolkata/India

http://ifexindia.com

65th Indian Foundry Congress 2017

February, 3-5, 2017, Kolkata/India

www.indianfoundry.org

6th International Foundry Congress & Exhibition

February, 15-16, 2017, Lahore/Pakistan

www.pfa.org.pk/info/6th-ifce/21/0

South African Metal Casting Conference 2017

March, 14-17, 2017, Kempton Park/South Africa

http://metalcastingconference.co.za

Advertisers‘ Index

Giesserei Verlag GmbH 52

GTP Schäfer GmbH 47

Hannover Milano Fairs Shanghai Ltd. 13

Imerys Refractory Minerals 18, 19

Metef Srl 9

TCT TESIC GmbH 29

50 Casting Plant & Technology 4 / 2016


K IMPRINT

PREVIEW / IMPRINT K

Preview of the next issue

Publication date: March 2017

With its state-of-the-art technical equipment the Schmiedeberg Gießerei has a unique abundance of possibilities in the production of castings

weighing a few kg up to almost half a ton (Photo: Michael Vehreschild)

Selection of topics:

M. Vehreschild: On the way to the intelligent factory

The Schmiedeberger Gießerei invested around 6.5 million euros in the efficiency of its business processes. With the new ERP system,

the foundry makes a decisive step towards an intelligent factory. And additional investments in robotics and 3-D printing processes

will follow.

M. Vehreschild: Basibüyük Group on expansion course

Foundries are now increasingly outsourcing their casting finishing processes. One of the first addresses in Germany, Austria, Switzerland and

the Netherlands is the Basibüyük Group from Mülheim-Kärlich. Within six years, the number of employees doubled to a total of 500 - with

the trend pointing upwards.

F. Hartung: Patented environmental technology for foundries

Foundries continue to be an important industry, but have to adhere to high environmental standards in many regions of the world. The

Copenhagen-based company Infuser has developed an innovative solutions that enable foundries to economically reduce contamination by

harmful substances or odors by up to 99.99 %.

Imprint

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ISSN 0935-7262

Casting Plant & Technology 4 / 2016 51


Are you ready for the future?

The GIESSEREI SPECIAL Research and Innovation with

specialist articles in German and English shows how new

knowledge can be successfully implemented economically.

Topics of the brand-new edition:

> What does Industry 4.0 mean in

casting technology?

> Salt cores in die-casting

> Intelligent Data Acquisition

(IDA)

> Determination of BTEX

from molding material

pyrolysis

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