Effect of T5 and T6 heat treatments on cold deformation of a thixocast aluminium alloy

Effect of T5 and T6 heat treatments on cold deformation of a thixocast aluminium alloy was investigated. A speroidisation of silicon particles and a redistribution of solute elements from the eutectic to the globule were observed on exposure to high temperatures. Hardness measurements revealed a delay in the precipitation process in T5 with respect to T6 due to lack of supersaturation. T5 aging treatments were found to give satisfactory results for elongation as the ductility values were comparable to that of T6. The results revealed better mechanical properties for the heat treated alloy in comparison to the alloy produced by other casting techniques