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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Mg_(12)Nd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。
The microstructure, annealing strengthening behavior and compressive deformation mechanism of Mg-5.3Nd alloy were studied by means of OM, XRD, SEM, EDS and room temperature compression test. The results show that Mg_ (12) Nd, the second phase of as-cast Mg-5.3Nd alloy, is basically eliminated after solution treatment at 550 ℃ for 8 h. After pre-compression-unloading-re-compression test, the compressive strength of Mg-5.3Nd alloy did not change obviously, while the pre-compression-unloading-annealing-recompression treatment significantly increased the compressive strength of the alloy and obtained the best reinforcement The effect of the annealing process is 180 ℃ / 4 h. In-situ metallographic analysis showed that the mechanism of recompression deformation of un-annealed samples was the obvious growth of pre-deformed twins. The pre-deformation of the sample after annealing, due to neodymium pre-deformable twin pinning effect, the mechanism of its re-compression deformation to the formation of new deformation twins.