{10ī2}拉伸孪晶对AZ31镁合金薄板成型性能的影响

Influence of {10ī2} Tensile Twins on Formability of AZ31 Magnesium Alloy Thin Sheets

通过沿横向（TD）预压引入{1012}拉伸孪晶,室温下做单向拉伸试验研究{1012}拉伸孪晶对AZ31轧制镁合金薄板显微组织和成形性能的影响。研究发现,预压板材中出现大量孪晶,因孪晶切割晶粒细化晶粒效应,板材的屈服强度（YS）、抗拉强度（UTS）和断裂伸长率（FE）均获得了不同程度的提高,应变硬化指数（n值）增加,塑性应变比（r值）减小,板材成形性能显著提高。

Pre-compression（PRC） were conducted along transverse direction（TD） to generate { 1012 } tensile twins. Then,the tmiaxial tensile tests were performed at room temperature to investigate the influence of {1012} tensile twins on themicrostructure and formability of AZ31 rolled magnesium alloy thin sheets. The results show that there are plenty of twins inpre-compressed sheets. Because of the effect of cutting and refining grain for twins, the yield strength （YS）, ultimate tensilestrength （UTS） and fracture elongation （FE） of the sheets improve in different levels, the strain hardening exponent（n-value）increases, and the lankford value（r-value） decreases. Thus, the formability of the sheets improves obviously.