The effects of Zr addition on the microstructures and mechanical properties of 75wt.%Ag-25wt.%Pd alloy was studied.
Grain size of the alloy was diminished with increasing amount of Zr addition, and it was notable when 0.2wt.% of Zr was added.
when 0.6wt.% of Zr was added, coarse Pd₃Zr intermetallic compound(hexagonal, ??, ??) was precipitated in the matrix, and fine Pd₂Zr intermetallic compound(body centered tetragonal, ??, ??) could be seen by aging treatment at 450℃.
Ultimate tensile strength of the alloy was increased with decreasing grain size until 0.2 wt.% Zr addition, but when an excess of Zr was added, ultimate tensile strength of the alloy was somewhat diminished despite of decreasing grain size.
So, we concluded that the grain size of the 75wt.%Ag-25Wt.%Pd alloy was diminished by the Zr addition and mechanical properties were increased with decreasing grain size, and the optimum amount needed for hardening was 0.2 wt.%.
|