The effects of S and Ir on the microstructures of Ag-Pd alloys were studied by optical micrographs and SEM Analysis. Ag-25%Pd alloy and a commercial alloy(A-2000) were selected. The segregation tendency of S in the grain boundary was investigated by AES and EDS. S and Ir concentrations are varied. Also, the effect of cooling rate on the microstructures of Ag-25%Pd alloy and A-2000 alloy was investigated.
The effects of Ir and S addition on the mechanical properties of Ag-25%Pd alloy and A-2000 alloy were investigated by tensile test. The fracture characteristics of each alloy were investigated by SEM Analysis. The compositions of several positions on the fractured surface were measured by EDS Analysis.
The refining effect of Ir appeared in Ag-25%Pd alloy when the concentration of Ir was more than 0.1%, and in A-2000 alloy when it was more than 0.07%.
The mechanical properties of Ag-25%Pd alloy were improved by addition of Ir and did not decreased in spite of S addition, while those of A-2000 were decreased by S addition.
The segregation tendency of S to the grain boundary decreased as increasing Ir content. The segregation of In and Zn in A-2000 alloy containing high S concentration did not occur while it occurred in the alloy with low S concentration.
