Hot working of an as-Cast Mg-2%Al alloy

Magnesium based alloys are being considered currently as replacements for aluminum alloy components in automobile industry, due to their high specific strength as compared to aluminum alloys. However, the utilization of Mg alloys is restricted due to their poor formability, and consequently these have been used mostly in the as cast condition. In order to increase the utilization of the wrought forms, it is necessary to develop optimum deformation processing conditions for producing defect free wrought products economically from the cast alloys. In the present study, the compressive deformation characteristics of as cast Mg-2wt% Al alloy with an equiaxed initial grain size of 150 +/- 10 mum have been studied in the temperature range of 573-723 K and at strain rates ranging from 10(-2) to 10 s(-1). The results are analyzed in terms of the existing theoretical hot working models together with the microstructural characteristics of the alloy. Furthermore, optimum. conditions for subsequent deformation processing have been identified based on a combination of mechanical data together with the deformed microstructures.