Effect of solid solution process on microstructure and properties of 6082 aluminum alloy

Abstract

In this paper, the effect of solid solution on the microstructure and hardness of 6082 aluminum alloy experiencing hot rolling were investigated by optical microscopy, scanning electron microscopy (SEM), energy spectrum analysis (EDS) and Stretching test. The results showed that the second phase (Mg2Si) in the experimental alloy is a soluble phase, and the Fe-containing impurity is an insoluble phase. After the single-stage solution treatment, the degree of solid solution, recrystallization and the size of recrystal grain increased with the increasing of solid solution temperature. It was found that when the temperature increases, the recrystallization took place, and the crystal grains become coarse, resulting in the disappearance of the rolling effect and the deterioration of the mechanical properties. Moreover, the 6082 aluminum alloy exhibits high quench sensitivity, which can be alleviated by the two-stage solid solution. The results showed that the optimized two-stage solution is (515 °C, 0.5 h) + (545 °C, 0.5 h) under the conditions of the existing experiments in this study. In addition, after aging at 170 °C for 8 h, the tensile strength reached a maximum of 349 MPa.