Effect of deformation on aging in Al-Mg2Si alloys.

The effects of deformation on the aging in five kinds of Al-Mg2Si alloys have been investigated by Vickers microhardness test and electron microscopy.In Al-0.4%Mg2Si alloy, the maximum hardness during aging was small.Both intermediate and equilibrium phases were detected in the specimen peak-aged at 473K without predeformation, though no equilibrium phase was observed in cold-rolled and peak-aged specimen.In Al-1.0%Mg2Si and Al-1.6%Mg2Si alloys, there were several combinations of cold-rolling and aging condition under which the maximum hardness of the non-deformed specimens was nearly equal to that of the deformed specimens.In Al-0.4%Mg2Si and Al-0.6%Mg2Si alloys, the age hardenability, which is given by the difference between the maximum hardness and the initial hardness is larger in cold-rolled specimen than in non-rolled specimen.However, the age hardenability of both Al-1.0%Mg2Si and Al-1.6%Mg2Si alloys is larger in non-rolled specimens than in rolled specimens.