CPT International 4/2019

PRESSURE DIE CASTING
a
c
b
Figure 4: Development of a
reinforced member for a
driver’s cabin. a) frame
head with member for driver’s
cabin, b) initial concept,
c) current geometry of
the ductile iron cast component
(weight saving: 15%).
Figure 5: New design of the
front suspension bracket
(grade: EN-AC-Al-Si10Mg
T6) (weight saving: 30%)
locking force of 2,000 t. Heat treatments,
as T 5 or T 6, for example, are
possible without restriction because the
mold filling technique reliably prevents
gas porosity in the castings.
The product portfolio for both cast
iron and aluminium comprises a wide
range of different large-series-produced
castings which comply with the latest
light-weighting requirements (Figures 1
and 2). Prototypes are produced by
means of a state-of-the-art laser sintering
system, which produces a 3-D printed
prototype ready to the installed
(Figure 3).
Light-weighting concept
In automotive engineering, the design
of structural vehicle parts is largely
determined by the static and the dynamic
load case, and, in particular, the
crash performance. Only the static load
case can be assessed by means of quasi-static
parameters, such as tensile
strength Rm, yield strength Rp or elongation
A5. The dynamically determined
material parameters, such as the supportable
medium stress amplitude,
depend on the notch factor of the designed
component. As the notch sensitivity
increases with increasing material
strength, high-strength materials are
unsuitable for light-weighting designs.
The decisive parameter is
the modulus of elasticity!
The modulus of elasticity (Young’s
modulus) depends on the graphite
form, i.e. compacted graphite iron, grey
cast iron or ductile iron. However, for
the graphite forms in the compact to
spherical range, the modulus is more or
less the same independent of the
strength of the material. Instead, for
light-weighting applications, the deformation
behaviour is more important.
This refers to the supporting effect, for
example, or the use of anisotropy to
evaluate the fatigue stress behaviour.
Fusion welding
with
filler material
Laser Electric arc Gas Fusion
welding
Compression welding
without
filler material
Magnetic
Arc
welding
Capacitor
discharge
welding
Figure 6: Applicable welding methods for joining (light-weight) castings with steel elements.
Examples of light-weighting
concepts
Its excellent manufacturing facilities
and materials competence enable Franken
Guss to determine in-house
whether cast iron or aluminium would
be the best suitable material for the
application on hand and to develop
application concepts by themselves.
Building on these capabilities, Franken
Guss has evolved from a service provider
to a development partner for its
customers. This includes simulations
using state-of-the-art techniques and
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