Effect of different heat treatment conditions on microstructural and mechanical behaviour of AZ63 magnesium alloy

Abstract

In this study, influence of different heat treatment conditions on microstructure, microhardness, yield strength, ultimate tensile strength, elongation and phase distribution of AZ63 magnesium alloy were discussed. All specimens were taken from as cast commercial AZ63 magnesium alloy. Solution heat treatment was applied at 400 °C for 16 h. After air cooling the specimens to room temperature, the specimens were aged at two different temperatures; 160, 190 °C and five different durations; 1, 3, 6, 9 and 12 h. The effects of heat treatment conditions on the mechanical and microstructural properties of AZ63 magnesium alloy were determined by tensile and microhardness tests, SEM, EDX and XRD analyses, respectively. It was observed that, after the solution treatment, a weak intermetallic phase of Mg17Al12 was dissolved almost totally in the matrix. During ageing, this phase precipitated in the grains and also on the grain boundaries homogeneously depending on the ageing temperatures and times.