中文摘要：

通过熔炼铸造及热挤压方法制备了Mg-13Gd-2Nd-2Cu（质量分数）镁合金。通过金相显微镜、扫描电镜及能谱分析、维氏硬度、拉伸性能测试等方法,研究了Mg-13Gd-2Nd-2Cu合金的铸态显微组织特征及退火温度对挤压态合金的组织与力学性能影响。结果表明：退火热处理促进了晶界处Mg5（GdNdCu）1相充分溶入α-Mg基体中。提高退火温度使基体晶粒发生再结晶长大,改变了Mg5（GdNdCu）1相的形态和分布。当退火温度超过500℃时,晶粒粗化并部分发生过烧现象。提高退火温度,会使挤压态合金的屈服强度有所降低。

英文摘要：

Mg-13Gd-2Nd-2Cu （mass fraction） alloy was prepared by casting and heat extruding. The as-cast microstructure and effects of annealing temperature on microstructure and mechanical properties of the alloy were stud- ied using optical microscope, scanning electronic microscope （SEM） equipped with energy dispersive spectroscope （ EDS）, Vickers hardness tests and tensile testing. The results showed that the Mg5 （GdNdCu）1 phases distributing along grain boundaries can dissolve into α-Mg through annealing treatment. With increasing annealing temperature, recrystallization grains grew up and the distribution of Mg5 （GdNdCu）1 phases varied. The grain of as-extruded alloy would be coarse and oversintering when the annealing temperature was over 500℃. Increasing annealing temperature, the yield strength of the alloy slightly decreased.