Figure 5. shows the microstructures of an
as-cast sterling silver alloy produced by investment
casting. The amounts of interdendritic eutectic
structure presented in these alloys tend to decrease
at high silicon (0.1-0.3wt%Si) addition, as seen in
Figure 5(c-d). Figure 6. shows that the metal mould
samples all have much finer dendrite structures,
finer grain size and consequently finer eutectic
structures. At high Si level Figure 7(d), interdendritic
eutectic has predominantly transformed and
appeared as a continuous structure. Comparing to
the standard sterling microstructure in Figure4(b),
micropores are significantly decreased with Zn and
Si addition to the sterling silver alloys. show the
improving of the microstructure by the castibility
as well as phase homogenization.