The effects of Zr content on solidification process of Al-Si-Mg-Mn alloy, and its microstructure and mechanical properties after aging treatment were investigated by means of numerical simulation, microstructure observation and mechanical property testing. The research results reveal that with increasing Zr content, the solidification path of the alloy become significantly different, and grains evolve from initial dendrites to equiaxed grains. After aging treatment at 175 ℃ for 7 h, an addition of Zr can significantly improve the hardness of the alloy. The addition of Zr promotes the precipitation of precipitates at lower aging temperature, which may be attributed to grain refinement of Zr, thus leading to improved diffusion efficiency. The main precipitates of the alloy are β″ phase and Q′ phase during peak aging.

aluminum alloy  /  lightweight  /  precipitation strengthening  /  grain refinement  /  Zr  /  Al-Si-Mg-Mn  /  aging  /  precipitates  /  microstructure and morphology