Abstract
The glod and palladium contents of Ag-Cu alloys have been standardized to 12 and 20wt%, respectively by all manufacturers.However, the contents of silver and copper vary from 45 to 55 wt% and from 10 to 20wt%, respectively, depending on the different amounts of silver and copper contents.Therefore, it is important to know the effect of silver/copper contents rate and the increase of gold contents not only for the alloy evaluation but also as a guideline for alloy development.This study investigated the relationship of heat treatment and strengthening of S-12 and Castwell M.C(12wt% Au-20wt% Pd-Ag-Cu alloy)to variations in the silver and copper contents of both alloys and to Alba 20 which contains 20wt% gold alloy(20wt% Au-Pd-Ag-Cu alloy).In 12wt% Au-20wt% Pd-Ag-Cu alloy, although Castwell M.C differs in silver and copper ratio from S-12, the characteristic curves representing the relationship between heat treatment temperature and mechanical properties were similiar.The strengthening mechanism of 12% Au-20% Pd-Ag-Cu alloys was induced by both age hardening and solid solution hardening, while that in the 20wt% Au-Pd-Ag-Cu alloy was only induced by the age hardening.
