Influence of heat treatment on microstructure and mechanical behaviour of hot-rolled Al-Mg-Si alloy

As cast Al-Mg-Si alloy was hot-rolled at a temperature of 400 degrees C. After rolling, the alloy was subjected to T6 heat treatment by solutionising at 530 degrees C for 2 hours followed by quenching in water media. Heat-treated rolled Al-Mg-Si alloy was subjected to microstructural studies, microhardness test and tensile properties (In rolling direction, 45 degrees and 90 degrees to rolling direction). It is observed that heat treatment of rolled Al-Mg-Si alloy increases microhardness up to a certain duration of ageing and further drops to lower hardness. On heat treatment, the rolled alloy exhibited maximum tensile strength in rolling direction in comparison with 45 degrees and 90 degrees directions to rolling. It is observed that hot rolling followed by T6 heat treatment of Al-Mg-Si alloy tends to impart higher tensile strength compared to previously reported experimental values or commercially available alloys for developing high strength lightweight material. Under peak-aged condition, yield strength of 410 MPa and UTS of 440 MPa was achieved in the present work which is significantly higher than values reported in previous works.