中文摘要：

通过OM、XRD、SEM、EDS以及室温压缩试验等方法对Mg-5.3Nd合金的金相组织、退火强化行为以及压缩变形机制等进行了研究。结果表明：550℃/8 h固溶处理后,铸态Mg-5.3Nd合金的第二相Mg12Nd基本消除。经预压缩-卸载-再压缩试验,固溶Mg-5.3Nd合金的压缩强度没有明显变化,而预压缩-卸载-退火处理-再压缩试验后,合金的压缩强度明显提高,并获得最佳强化效果的退火工艺为180℃/4 h。原位金相分析发现,未退火试样的再压缩变形机制表现为预变形孪晶的明显长大。而预变形试样退火后,由于钕元素对预变形孪晶的钉扎作用,其再压缩变形机制以新变形孪晶的形成为主。

英文摘要：

The microstructure,annealing strengthening and compressive deformation mechanism of Mg-5.3Nd alloy were investigated by OM, XRD, SEM/EDS and room temperature compression test. The results show that the main second phase in as-cast Mg-5.3Nd alloy is Mg12 Nd and the optimal solution treatment is 550 °C/8 h for eliminating the second phases. With pre-compression-unloading-recompression, the compressive strength does not change obviously; however, after pre-compression-unloading-annealing-recompression, the compressive strength increases remarkably. The optimal annealing process is 180 °C/4 h. The in-situ optical micrographs indicate that the preformed twins in the pre-compressed Mg-5.3Nd alloy without annealing obviously grow up during the subsequent compression, whereas after annealing treatment the second compression deformation is proceeded by the initiation of the new twins rather than the growth of the preformed ones for the diffusion segregation of Nd element in the twin grain boundary during the annealing process.