Mg-Al-Ce-Y基压铸合金的微观结构稳定性和力学性能(英文)

With the aim to further improve the mechanical properties of Mg−Al−RE-based alloy, Mg−3.0Al−1.8Ce−0.3Y−0.2Mnalloy was prepared by high-pressure die-casting technique. The microstructure, thermal stability of intermetallic phases andmechanical properties were investigated. The results show that the alloy is composed of fine primary α-Mg dendrites and eutectic inthe interdendritic regions. The intermetallic phases in eutectic are Al11(Ce,Y)3and Al2(Ce,Y) with the former being the dominant one.The thermal stability of Al11(Ce,Y)3is conditioned. It is basically stable at temperature up to 200 °C within 800 h, while most of theAl11(Ce,Y)3intermetallics transform to Al2(Ce,Y) at higher temperature of 450 °C for 800 h. The alloy exhibits remarkably improvedstrength both at room temperature and 200 °C, which is mainly attributed to the reinforcement of dendrite boundaries with Al11(Ce,Y)3intermetallics, small dendritic arm spacing effect as well as the solid solution strengthening with Y element