Effects of Solution and Two-Stage Ageing Treatment Process on Microstructure and Properties of 6061 Aluminum Alloy

Comprehensive performance of 6061 aluminum alloy was improved by solution treatment and two-step ageing treatment in this paper . The effects of different thermal processing parameters on the microstructure and mechanical properties of 6061 aluminum alloy were studied. The experimental results show that the optimal process of solution treatment for 6061 aluminum alloy is heated at 500°C for 10min. After first-stage aging, the hardness measurements and microstructure analysis results show that the hardness increased with increasing aging temperature, and reached peak value at temperature 180°C for 10h, while in the second-stage ageing treatment, the sample got the ageing peak value at 220°C for 1h. After two-stage treatment, the grains of 6061 aluminum alloy became uniform and fine and the second phase distributed along the grain boundary and play an important role of dispersion strengthening. Above all, the optimal heat treatment process of 6061 aluminum alloy is solution treated at 500°C for 10min, as well as ageing at 180°C, 10h and 220°C, 1h