中文摘要：

采用100 k N servo-hydraulic MTS型试验机对挤压态AZ31镁合金进行温度为350℃、应变速率为0.3 s-1和不同应变量下的热压缩;利用X射线衍射（XRD）测量不同应变量下的织构,并利用取向分布函数计算其织构类型,分析织构转变;通过电子背散射衍射技术（EBSD）分析孪生的形成情况。同时,计算不同滑移系和孪生的斯密特因子,分析不同滑移系和孪生开启的先后次序。结果表明：变形初期,由于拉伸孪生的出现导致（0001）]0110[和（0001）]0112[织构的形成,并随应变量的增加,发生动态再结晶,）0101（[0001]和）0121（[0001]纤维织构完全由（0001）]0110[和（0001）]0112[织构代替;在变形初期,大部分晶粒先产生拉伸孪生,接着发生二阶锥面滑移。

英文摘要：

The hot compression test was performed on 100 kN servo-hydraulic MTS test machine at temperature of 350℃ and strain rate of 0.3 s-1 under different strains. X-ray diffraction （XRD） was used to measure texture. Then, the texture type under different conditions was also calculated using orientation diffraction fimction under different conditions, aiming to study the texture transformation. The electron back-scattering diffraction （EBSD） was used to analyze twinning. Schmid factor for different slip systems and twinning were calculated to determine the order of initiation of deformation modes. The results indicate that the extension twinning is observed at the early deformation stage, mainly contributing to the formation of （0001）[1010] and （0001）[2110] texture. （01110）[0001] and （1210） [0001] fiber texture are finally replaced by （0001）[1010] and （0001）[2110] texture as the initiation of dynamic recrystallization. At the beginning of deformation, substantial grains firstly occur extension twinning, followed by 2nd-order pyramidal slip.