Studies on Cadmium and Silver Trace Element Modified AZ91C Magnesium Alloy

Summary

The mechanical properties of AZ and AM series of alloys were found to decrease at temperatures exceeding 120-130 °C [11]. This behavior has been attributed to the grain boundary sliding of the magnesium alloys and the phase Mg₁₇Al₁₂, which has a melting point of approximately 460 °C and found to be comparatively soft at higher temperatures. This softening behavior of the phase Mg₁₇Al₁₂ did not serve the purpose of pinning down the grain boundaries. Hence many researchers have come out with different suggestions for improving the creep behavior of AZ and AM series of alloys [10-12]. The addition of 1 % calcium improves the creep strength of Mg-Al alloys but makes them susceptible to hot cracking [12]. In several alloying systems addition of cadmium and silver offered an improvement in grain refinement and good mechanical properties [14]. Thus it is expected that addition of these elements to magnesium alloys could have beneficial effects on mechanical properties. Thus the present study aims at evaluating the effect of cadmium and silver trace additions on AZ91 alloys.