Tensile and Isothermal Fatigue Behaviors of Mg-12Gd-3Y-0.5Zr Alloy at High Temperature

Xiaoming Yang1)?, Huajie Yang1), Fan Yang1), Shuming Yin1), Wei Wang1), Shouxin Li1), and Qudong Wang2) 1) Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China 2) National Engineering Research Center of Light Alloys Net Forming, Shanghai Jiao Tong University, Shanghai 200020, China

摘 要：Tensile and isothermal fatigue tests were carried out on an as-rolled Mg-12Gd-3Y-0.5Zr alloy and its heat-treated counterpart at different temperatures. The experimental results show that the ultimate tensile strengths of two alloys decrease very slowly with increasing temperature up to 200?C. The ultimate tensile strength of heat-treated Mg-12Gd-3Y-0.5Zr is slight lower than that of as-rolled counterpart; however, the fatigue strength of heat-treated alloy is higher. The mechanism of fatigue failure was investigated by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. It shows that cyclic slip combined with environmental effect may be the main crack initiation mechanism.

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