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.