CPT International 02/2019

COMPONENT DEVELOPMENT
Photo: Audi AG
Die-cast components produced by DGS Druckguss Systeme from St. Gallen.
Aluminum structural castings:
integrated development
of component and process
The work behind a casting award
Klaus Vollrath, Aarwangen, Switzerland
On the occasion of the Euroguss
2018 trade fair in Nuremberg, on
15 January 2018, the German
Association of the Aluminium Industry
awarded first prize in the Aluminium
Die-Casting Competition to a casting
jointly developed by AUDI AG and DGS
Druckguss Systeme AG, St. Gallen, Switzerland.
The large and extremely
thin-walled structural element developed
for the new Audi A8 has a wall thickness
that is mostly only 1.8 - 2 mm, and it
there fore only weighs 3043 grams, despite
dimensions of 797 x 437 x 304 mm.
Just as interesting as the component itself,
however, is the development that lies
behind it, as a conversation with Markus
Heim, Key Account Manager, and Axel
Schmidt, Technology Manager at DGS,
reveals.
“What was special about the development
of the new component for the
Audi A8 was the integrated development
both of the product itself and the production
process, in close collaboration
with our customer Audi,” explains Markus
Heim, Key Account Manager at DGS
Druckguss Systeme. Audi took the decision
to approach this project together
with DGS at the end of 2015, after DGS
made an appropriate offer. The component
is a large but very thin-walled structural
casting that connects the C- and
D-pillars of the new Audi A8 (Model D5).
The structural element also redirects the
safety belt and supports the rear damper
strut via three threaded rings, as well as
accepts the parcel shelf, rear panel and
the hinge of the tailgate. Additional
requirements included as low a weight as
possible compared to the element previously
used, necessitating low wall thicknesses.
The prerequisite for this was the
use of a special high-strength alloy in
combination with a new heat treatment
process. Audi had already begun developing
this new type of alloy (AlSi10MnMgZnZr)
in 2011/2012. In addition to the
material, it was also essential to implement
an evolutionary modification of
the heat treatment process. Trials were
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