变形条件对AZ31镁合金冷压缩过程中孪生的影响

Effect of deformation conditions on twinning of AZ31 magnesium alloy during compression test

在新三思拉伸试验机CMT-5150上对均匀态AZ31镁合金进行室温压缩试验,研究了在变形量分别为5%、7.5%、10%、12.5%、15%以及变形速率分别为0.5、1、2、4mm/min时压缩变形组织中孪晶的形态与分布。结果表明:在压缩变形初期,只有少量晶粒内出现孪晶,孪晶较宽;而在压缩变形末期,孪晶几乎分布于所有晶粒中,且出现了细而长的孪晶。孪晶分数随变形程度的增大而上升。随着变形速率的增大,孪晶形态变细,且其密度增大,试样的屈服强度和抗压强度都升高。

Deformation twinning of homogenizing magnesium alloy AZ31 is respectively investigated by compression at room temperature with different deformation degrees from 5% to 15% and different deformation rates from 0.5 to 4mm/min.The results show that thick twins exit in a few amount of crystals at the beginning of the deformation. The thin-long twins and the thick twins appear at the end of the deformation,and they can be observed in almost all crystals. With increasing compressing rates,the yield strength,compression resistance fracture strength and density of twins increased,and twins become thin.