The heat treatment of Al-7%Si-0.3%Mg alloy

Abstract

T6 conditions were examined on the Al-6.85%Si-0.30%Mg-0.20%Fe-0.12%Ti-1.006%Na alloy castings to select an optimum heat treating condition for automobile wheels. Solution heat treating at 540°C for 9hr and quenching into cold water (15°C) as soon as possible are recommended. The elongation and Charpy impact value are reduced by quenching in hot water or quenching after prolonged delay time. Aging at 180°C for 6hr ensures the highest strength, and aging at 140°C for 4hr does high elongation and impact strength.