To observe the changes of Vicker´s hardness number by heat treatment on 4 commercial silver-palladium alloys (JWE, JWG, SS, Palliag M), and confirm the existance of precipitates with the changes of microstructure metallographycally, specimens were annealed at 800°C for 10 minutes and then heat treated at 200°C, 400°C, 600°C and 800°C for 15 minutes, 30 minutes, 45 minutes or 60 minutes respectively.
Microvicker´s h, rdness numbers were measured on each heat treated specimens and light microscopic views for microstructure and precipitates were taken.
The following conclusions can be drawn:
1. Effect of heat treatment on the rise of \Ticker´s hardness number was significant on Ag-Pd-Cu alloy than Ag-Pd alloy.
2. The optimum temperature of heat treatment for silver-palladium alloy was 400°C and the next one was 800°C.
3. Increase of the time for heat treatment (maximum 60 minutes) did not show the rise of Vicker´s hardness number.
4. Thin lamellae precipitates were formed and observed on the surface of Ag-Pd-Cu alloy after heat treatment.
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