Aging-Induced Hardening of Transition-Metal-Containing Al–Mg–Si Alloys Subjected to Deformation under Different Conditions

Abstract

Metallographic analysis, hardness and electrical resistivity measurements, and tensile tests are used to study the behavior of Al–Mg₂Si alloys with (Sc + Zr) transition metal additions during aging performed after preliminary deformation under different conditions. It is shown that the decomposition of the supersaturated solid solution in the Al–Mg₂Si alloys with (Sc + Zr) transition metals and without them occurs in the same manner. However, the strength properties of the alloys with transition metals are higher than those of the alloys free from the transition metals because of substantial refining of solid-solution grains and a high density of dispersoid (Sc_{1 –x}Zr_x)Al₃ aluminide particles. A peak hardness is observed for the alloys after quenching, equal channel angular pressing (ECAP), and aging. However, cold rolling after quenching before aging leads to an increase in the strength properties to a greater extent than ECAP performed under the same conditions.