manufacturer Oskar Frech, who is both board
chairman of the VDMA foundry machine trade
association and a member of the board of
the VDMA additive manufacturing task force,
stresses in an interview with the magazine
Giesserei. For example, Frech uses 3D
printing to produce a complex key component
for its low-sprue FGS tool technology that
economises on recycled material (e.g.
aluminium or magnesium).
The mould plays a key role in the die casting
process. It is important that the castings solidify
as quickly as possible. The process time for a
component can be shortened by faster cooling,
while the quality of the casting is improved at
the same time too. This depends on adequate
heat removal in the casting mould, which is
traditionally achieved via cooling holes. Due to
process constraints, however, there are limits to
how close to the shaping surface that cooling
holes can be produced. Additive manufacturing
can help here, because cooling close to the
surface is possible even in critical areas of the
mould thanks to the tremendous amount of
design freedom the process provides.
STEEL INDUSTRY: NUMEROUS OPPORTUNITIES WITH
3D PRINTING
The situation in the hot forming of steel plate is
not much different than in die casting. Cooling
close to the surface increases productivity
and quality here too. Additive manufacturing
has therefore been a standard process in the
tool production operations of German car
manufacturers for a long time now.
Steel companies are discovering additive
manufacturing as an additional area of
operation to an increasing extent. The
Austrian technology and steel company
voestalpine, for example, chose Düsseldorf
to be its corporate centre of excellence for
metal additive manufacturing two years ago.
Initial results have been achieved. Together
with the development service provider Edag
and Simufact, the specialist for simulation
software, the Austrian company has developed
a lightweight bonnet hinge with integrated
pedestrian protection that is produced by
additive manufacturing.
Rosswag from Pfinztal near Karlsruhe,
the biggest open die forging company in
Southern Germany, demonstrates with additive
manufacturing how the best of two worlds can
be combined. The long-established company
manufactures new products by linking the two
manufacturing processes forging and selective
laser melting of steel powder. Solid, materialrich,
conformal components are made by open
die forging. The production of a heavy-duty,
forged workpiece with appropriate grain flow
is followed by additive manufacturing via a 3D
printer in order to supplement the complex
structures. In the case of an impeller with
additively manufactured vane structures,
for example, channels were incorporated to
influence flow characteristics.
PRINTED SAND MOULD FOR A LARGE DIESEL CYLINDER HEAD FROM MAN: THE MOULD WITH
DIMENSIONS OF 1,460 X 1,483 X 719 MM WAS MANUFACTURED ADDITIVELY IN 29 HOURS BY THE
BINDER JETTING PROCESS USING A SAND PRINTER.
PHOTO: VOXELJET
STEEL PLANT MANUFACTURERS: SIGNIFICANT
REDUCTION IN THE WEIGHT OF DYNAMICALLY
MOVING COMPONENTS
The most recent member of the additive
manufacturing club is SMS group, the
specialist for metallurgical machine and plant
manufacturing. The leading manufacturer of
steel and rolling mill technology has installed
a new pilot plant for metal powder production
at its location in Mönchengladbach, Germany.
The company has several objectives with the
powder atomisation plant. On the one hand,
SMS aims not only to produce high-purity
metal powder for additive manufacturing
on behalf of customers but also to develop
and test new materials. The company can
take advantage in this context of decades of
experience with the atomisation of iron powder
and/or sintering. The extensive metallurgical
know-how available within the corporate group
and the wide-ranging expertise in thermal
process engineering are a good basis too. On
the other hand, the plant manufacturer would
like to supply the rapidly growing market for
metal materials for additive manufacturing
processes by marketing powder atomisation
equipment.
Last but not least, the in-house metal powder
production facilities are a link in the company’s
additive manufacturing process chain. The
plant manufacturer has already started
to exploit the potential of this innovative
new technology by producing additively
manufactured spraying nozzles for swaging
presses. Spraying nozzles remove scale from
dies, cool the surface, apply lubricants and
dry the dies. The original spraying nozzle was
a solid and heavy component. Very light and
compact spraying nozzles can be produced
by three-dimensional printing that are
customised precisely to meet the requirements
of individual dies. The company reports that
use of the 3D spraying nozzles, which can be
produced either from plastic or from metal in
accordance with the customer’s needs, leads
to a reduction in cycle time as well as to an
extension of tool service life in the swaging
process.
SMS reveals that the results of other projects
are no less promising. A conformal design with
integrated nozzles is an outstanding feature of
a new roller cooling pipe for wire rolling mills,
for example. Thanks to the use of alumide, a
combination of aluminium and plastic powder,
the structure is easier and more cost-effective
to produce than conventional components. In
the steel converter field, it has been possible
to reduce the size of the SIS injectors used
for molten steel by 60%, while they can be
produced from a single part instead of eight
parts. And pipe welding machines from SMS
group can also produce pipe diameters of 14
inches or less in future thanks to printed parts,
because smaller but more efficient lubricating
rings for the expander tools are possible in a
hybrid structure produced in a combination of
additive and conventional manufacturing.
LARGE DIESEL CYLINDER HEAD: CAST IRON
PART WEIGHING MORE THAN ONE TONNE.
PHOTO: VOXELJET
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