Finishing - May-June 2022

28 CORROSION PROTECTION
component, by adding corrosion protection
you have the ability to further extend that
lifetime which is far more sustainable than
replacement.
Types of metals at risk of
corrosion.
Carbon and high strength steels are very
susceptible to corrosion because these alloys
have been designed primarily for strength and
lack the chromium content found in stainless
steels that prevent corrosion. The aerospace
industry is a prime example of the necessity of
corrosion prevention, due to the wide variety
of environments that materials are exposed to,
especially the high strength steel landing gears
on planes. With this type of steel, hydrogen
embrittlement adds an element of risk.
Another alternative electroplated deposit for
corrosion protection is tin zinc, however, one
of its disadvantages is it has less optimum
wear properties when compared to zinc nickel.
Corrosion protection relies heavily on
testing, and it produces a great deal of data
which needs to be analyzed. This research
helps to benefit businesses within engineering,
manufacturing, and the aerospace industry.
R&D departments’ regularly work on different
projects and corrosive scenarios. One major
product that the team at SIFCO ASC are
involved with is a cadmium replacement
technology – a zinc nickel alloy. The two
primary forms of corrosion that are most likely
to affect substrates that have traditionally been
electroplated with cadmium are hydrogen
embrittlement and general corrosion. By
adjusting and homing in on a variety of
plating parameters, zinc nickel has met or
exceeded cadmium selective plating, especially
during salt spray testing.
Optimizing this deposit and plating
parameters, along with the subsequent
research and testing are driven by regulations
which aim to reduce the use of harmful
chemicals like cadmium, which is a
carcinogen, whereas zinc nickel is less harmful.
A lot of the testing within zinc nickel helps to
support businesses with their corrosion
protection goals and, in some instances, helps
them work with the military to roll the system
out where advances in corrosion protection
are vital.
Translating the data into real
world problem solving.
Data gained from testing can be used to
work on other projects that will help to
advance corrosion protection. The ASCS
(Advanced Solution Control System) is one
such project, which is a fully automated,
dripless, selective electroplating system from
SIFCO ASC. One of the many benefits of this
type of technology is that due to the dripless
design the plating solution is vacuumed away
during the plating process, allowing an even
tighter control on testing parameters and
reducing hazardous waste.
Additional testing has involved looking at
the effects of the appearance and morphology
of the deposit and how it affects the overall
performance. As well as ensuring that the part
or component is protected and performs to
the highest standard possible, in some cases it
is important that the end result looks
aesthetically pleasing which is why further
testing here is key.
Supporting the customer.
With a considerable amount of time and
research going into the development of
corrosion protection technologies, the industry
and customers’ needs are always changing
which in turn will change our priorities and
determine how we can advance selective
electroplating further. As a business SIFCO
ASC helps customers to meet their selective
plating requirements, by using engineering
expertise and continuous innovation through
R&D.
This is important during the concept,
design, and production phase of a project.
Our process is a vital resource when you need
to enhance, repair, and rebuild your critical
components. We work closely with our
customers to develop solutions to fulfil specific
application requirements. Ultimately, plating
can be used to repair, enhance, and increase
the lifecycle of a product, protecting them
against the onset and risk of corrosion,
thereby improving performance and reducing
component failure.
The future of corrosion
protection.
There is so much more to learn when it
comes to corrosion protection, particularly
focusing on other types of materials and
substrates that are less susceptible to
corrosion. The use of titanium is one
alternative that companies might look at, as it
forms a natural protective layer of oxidation.
Testing the effects of plating on titanium is
ongoing, with the intended use of having
natural corrosion protection plus the benefit of
additional electroplated deposits on top that
can serve a variety of purposes. The increasing
use of titanium is in large part because it is
inert, strong, and lightweight in comparison to
steel.
One other material that has been identified
for plating on is graphite epoxy composite
materials, which are conductive and very
lightweight, and ideal for aerospace
applications. This application presents similar
challenges to plating on titanium and while
some preliminary testing has been conducted,
the results still need to be studied and
developed further. Corrosion presents a
significant challenge within engineering and
manufacturing industries and scientists and
corrosion prevention engineers are working
hard to find ways to slow the process down.
Innovations in corrosion protection
processes and testing will continue to be a
driving force for success. SIFCO ASC
continues to focus its attentions on corrosion
protection research and development, working
closely with customers to develop effective
solutions to their challenges. Corrosion will
continue to present engineering and
manufacturing challenges, but with
advancements in plating technology such as
with the ASCS more is being done to slow
down and reduce the effects of corrosion.
Finishing - May/June 2022