挤压态AZ31镁合金变形组织演变机制

发布时间：2018-04-29 07:06

本文选题：镁合金 + 孪生　；参考：《材料热处理学报》2017年01期

【摘要】：研究了挤压态AZ31镁合金在压缩过程中的组织变化及其演变机制,探讨了孪生对加工硬化的影响。结果表明,当应变量小于4%时,孪晶含量随应变增大而增多;此后,随应变增加,孪晶含量反而逐渐减少,显微组织分析表明发生了退孪生现象。但织构分析表明,镁合金在压缩过程中并没有发生退孪生。孪晶长大与合并模型被用于解释组织分析显示的孪晶产生和消失现象。在挤压态镁合金的压缩过程中,孪晶的长大与合并导致基体几乎被消耗完毕,大部分基体转变成了孪晶组织,孪晶合并成片,以至于在显微组织观察中产生了孪生先产生后消失的假象。研究还表明,在孪生过程中镁合金的晶体取向发生86.3°的转变,使得镁合金从软取向变成了硬取向,这种取向的转变是镁合金压缩变形过程加工硬化的主要原因。
[Abstract]:The microstructure change and evolution mechanism of extruded AZ31 magnesium alloy during compression were studied, and the effect of twinning on work hardening was discussed. The results show that the twinning content increases with the increase of strain when the strain is less than 4 and decreases with the increase of strain. However, the texture analysis showed that the twin did not degenerate in the compression process of magnesium alloy. Twin growth and amalgamation models are used to explain the twin formation and disappearance in tissue analysis. In the compression process of extruded magnesium alloys, the growth and amalgamation of twins lead to almost complete consumption of the matrix, and most of the matrixes are transformed into twin structures, and the twins are merged into pieces. So much so that in the microstructure of the appearance of twinning first and then disappear. The results also show that the crystal orientation of magnesium alloy changes from soft orientation to hard orientation during the twinning process, which is the main reason for the work hardening of magnesium alloy during compression deformation.
【作者单位】：贵州理工学院材料与冶金工程学院;重庆大学材料科学与工程学院;贵州理工学院机械工程学院;
【基金】：国家自然科学基金(51501045) 贵州省自然科学基金(黔科合J字[2015]2067号) 贵州理工学院高层次人才科研启动经费项目(XJGC20141102) 黔科合人才团队(2015)4008号
【分类号】：TG146.22

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