The RDC samples had very little or were free from porosity.
This made it possible to enhance mechanical properties through
heat treatment. Both T5 and T6 heat treatments were carried
out on the RDC A357 samples. The tensile test results of the
heat-treated samples are summarised in Table 2. Generally, in
comparison with the mechanical properties of the as-cast samples,
RDC samples with T5 treatment have substantially higher
yield strength and tensile strength, but a lower elongation. Further
improvement of strength of RDC samples can be achieved
by T6 treatment, but with some sacrifice of ductility compared
with as-cast conditions.