Microstructure and mechanical properties of a cast heat-resistant rare-earth magnesium alloy  

作　　者：Xiao-ping Zhu Jun-qing Yao Hai-long Wu Xin-wang Liu Hua Liu Zi-tian Fan Shu-lin Lü Kai Wang Zi-dong Wang 

机构地区：[1]School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]State Key Laboratory of Materials Processing and Die&Mould Technology,School of Materials Science and Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [3]Dekai Intelligent Casting Co.,Ltd.,Zhuozhou 072750,Hebei,China [4]China Iron and Steel Research Institute Group,Beijing 100081,China [5]Guangdong Hongtu Wuhan Die-casting Co.,Ltd.,Wuhan 430207,China

出　　处：《China Foundry》2023年第4期289-298,共10页中国铸造（英文版）

基　　金：support of the National Natural Science Foundation of China(Grant number 52071088)。

摘　　要：Microstructure,mechanical properties and phase transformation of a heat-resistant rare-earth(RE)Mg-16.1Gd-3.5Nd-0.38Zn-0.26Zr-0.15Y(wt.%)alloy were investigated.The as-cast alloy is composed of equiaxedα-Mg matrix,net-shaped Mg5RE and Zr-rich phases.According to aging hardening curves and tensile properties variation,the optimized condition of solution treatment at 520℃for 8 h and subsequent aging at 204℃for 12 h was selected.The continuous secondary Mg5RE phase predominantly formed at grain boundaries during solidification transforms to residual discontinuousβ-Mg5RE phase and fine cuboid REH2particles after heat treatment.The annealed alloy exhibits good comprehensive tensile property at 350℃,with ultimate tensile strength of 153 MPa and elongation to fracture of 6.9%.Segregation of RE elements and eventually RE-rich precipitation at grain boundaries are responsible for the high strength at elevated temperature.

关 键 词：heat-resistant magnesium alloy rare earth microstructure phase transformation tensile property strengthening 

分 类 号：TG146.22[一般工业技术—材料科学与工程]