ADDITIVE MANUFACTURING
LIGHTWEIGHT STRUCTURE WITH
ADDITIVE MANUFACTURING: VW CADDY
DEMONSTRATION VEHICLE WITH AN
EXTEMELY STRONG FRONT END STRUCTURE
MADE FROM THE 3D-PRINTED HIGHPERFORMANCE
ALLOY SCALMALLOY.
IT TOOK ONLY 9 MONTHS TO COMPLETE
IMPLEMENTATION OF THE IDEA IN A
CONVERTED VEHICLE.
PHOTO: CSI
is applied in layers to produce a soundly built
component.
The Berlin company Gefertec is looking to increase
manufacturing speed in the additive processing of
metals. The 5-axis lines produced by the expert for
additive manufacturing technologies weld wire in
layers by the electric arc process. The workpieces
produced in this way have outlines that are very
close to the final shape, which reduces the time
and tooling operations required for subsequent
machining.
FOUNDRY: DIRECT AND INDIRECT ADDITIVE
MANUFACTURING PROCESSES
The foundry industry can benefit from additive
processes in several different ways. Direct additive
manufacturing processes give foundries the
opportunity to include individual parts or parts
that are needed in small quantities in their product
portfolio too. In the case of indirect processes, on
the other hand, they use additive technologies to
produce moulds and cores out of sand as well as
models out of plastic. Hybrid technologies involving
a combination of conventional casting and additive
manufacturing processes have further potential.
In order to take greater advantage of the potential
that aluminium has to produce lightweight
structures in automotive manufacturing, the
aluminium producer Trimet is working on the
development of a hybrid process chain to link die
casting and additive manufacturing. The approach
adopted in the context of the joint “CastAutoGen”
project specifically involves the incorporation of 3D
printed structures in a die cast component.
German industry holds a prominent position
among the producers of additive manufacturing
systems, as the BDI (Federation of German
Industries) concludes in a position paper. The
country’s market share is about 70% with powder
bed systems. The country's world leaders among
3D printing manufacturers include Concept Laser
(metal), EOS (metal and plastic), SLM Solutions
(metal) and Voxeljet. Voxeljet has specialised
in foundries and markets 3D printers for the
production of sand moulds and cores as well as
of plastic models for investment casting by the
lost-wax process.
In order to produce a casting, what are needed
are a mould and the appropriate cores to form
the cavities in the component that is being cast.
In classic sand casting, the moulds and cores are
made from quartz sand, which is strengthened
by a special bonding agent. While fully automatic
moulding machines and automatic core shooting
machines are standard features at modern
foundries for the mass production of car engines,
for example, it is rarely an economic solution to
use automatic equipment for prototypes and small
batches. 3D printing is an increasingly common
alternative here. Sand moulds and cores of any
complexity are manufactured from the CAD dataset
via a layering process. Toolless manufacturing
of this kind provides high flexibility as regards
numbers, design and versions and permits the
production in exactly reproducible quality of
complex moulds and cores with practically any
geometry. Voxeljet talks about cost savings of up
to 75% in the 3D printing of moulds and cores
made from sand for small batches.
The printing of sand moulds and cores is a highly
suitable option for development operations. The
iron foundry Düker with locations in Karlstadt
and Laufach in Germany, for example, does not
use models any more in the casting it carries
out for customers. The CAD dataset is all that
is needed to produce the sand moulds that are
manufactured additively. As a result, new products
can be implemented in castings from computer
files within a short time and can then be machined
for trial purposes. Geometric adaptations are
simple to carry out and recasting is then possible
once the design data have been changed and
another mould has been printed. Düker reports
that development time is reduced significantly by
this process. It is apparently standard procedure
to produce initial samples within a few weeks, for
which months are needed in the series process.
Die casting with reusable moulds made
from tool steel benefit from 3D printing too.
“Additive manufacturing is creating tremendous
opportunities for die casting companies," as Dr.
Ioannis Ioannides, ceo of the die casting machine
PREPARATION OF THE BODY: A FIRSTGENERATION
VW CADDY WAS GUTTED
COMPLETELY AND A NEW FRONT END
STRUCTURE WAS FITTED.
PHOTO: CSI
22 August 2018