Thixoforming : Semi-solid Metal Processing

step-shot experiments. It is also suitable for first tool material examinations owing to
its segmented inserts.
9.3.3.1 Investigations on Mould Filling Behaviour (Step Die)
The segmented step die consists of six interchangeable inserts with different
ramps. The test pieces produced have wall thicknesses between 0.5 and 25 mm and
represent the wall thickness range of components manufactured industrially. The
step form is used to analyse the influence of changing flow crosscuts, wall thicknesses
and therefore different metal velocities on the mechanical qualities and the
microstructure.
The part illustrated in Figure 9.17 was produced from the cold work steel
X210CrW12. At a constant piston velocity of 0.05 m s 1 , the metal velocity increases
Figure 9.17 Thixocast X210CrW12 steel part at a solid fraction of
about 70% (Tc 1290 C). The component shows outstanding
surface quality and dimensional accuracy. The micrographs show
a slight increase in liquid content towards the tip of the step
specimen associated with an increasing fraction of fine dispersed
solid particles.
9.3 Thixocasting of Steel Alloysj327