AZ31镁合金板材双向循环弯曲的孪晶组织及织构  

Twins and Texture of AZ31 Magnesium Alloy Sheet Deformed by Bidirectional Cyclic Bending Technology

作　　者：王忠堂[1] 马康[1] 梁海成[1] 张士宏[2] 

机构地区：[1]沈阳理工大学,辽宁沈阳110159 [2]中国科学院金属研究所,辽宁沈阳110016

出　　处：《稀有金属材料与工程》2016年第10期2746-2751,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51575366);沈阳市科技计划项目(F14-231-1-32)

摘　　要：采用等温双向循环弯曲工艺(bidirectional cyclic bending technology,BCBT)改善了AZ31镁合金板材的微观组织、织构和力学性能。循环弯曲变形能够产生压缩变形与拉伸变形的交替变化,使镁合金材料发生压缩变形→孪晶组织形成→发生动态再结晶→孪晶消失→晶粒细化的组织演变过程,形成分布均匀的细小的晶粒组织,改善了镁合金材料性能。AZ31镁合金板材在变形温度为483 K时经过3个道次的等温双向循环弯曲变形后,基面织构得到明显弱化,织构强度由原始9.59降低到变形后3.54,平均晶粒尺寸为12.2μm。在变形温度443 K,经过1个道次变形后,AZ31镁合金板材的抗拉强度为325 MPa,屈服强度为225 MPa。与原始坯料力能参数相比,抗拉强度提高了19%,屈服强度提高了28%。当变形温度483 K循环变形3道次时,材料的伸长率为17.1%,比原始材料提高了42%。Bidirectional cyclic bending technology（BCBT） had been used to improve the microstructure and texture and mechanical properties of AZ31 magnesium alloy sheet. When AZ31 Magnesium alloy sheet deformec by BCBT, the recrystallization had occurred in twins boundary, and across area between twins boundary and crystal boundary, and across area between twins and twins. And grain size was less than twins width. When deformation temperature of BCBT was 523K, the recrystallization nucleation had occurred in crystal boundary and grown up quickly. When deformation temperature was 483K and deformation process was 3 times, basal texture of AZ31 magnesium alloy sheet was weakened, and texture intensity was reduced from 9.59 to 3.54, and average grain size was 12.2μm，and elongation ratio was 17.1% at room temperature. .

关 键 词：AZ31 镁合金 双向循环弯曲 孪晶组织 织构 

分 类 号：TG146.22[一般工业技术—材料科学与工程]