预变形对双峰分离非基面织构AZ31镁合金板材室温力学行为及微观组织演变的影响  

Effect of Pre-Deformation on Mechanical Behavior and Microstructure Evolution of AZ31 Mg Alloy Sheet with Bimodal Non-Basal Texture at Room Temperature

作　　者：汪丽佳 胡励 苗天虎 周涛[1] 何曲波 刘相果 WANG Lijia;HU Li;MIAO Tianhu;ZHOU Tao;HE Qubo;LIU Xiangguo(College of Materials Science and Engineering,Chongqing University of Technology,Chongqing 400054,China;Chongqing Material Research Institute Co.Ltd.,Chongqing 400707,China;Chongqing Zhonglei Tech.Co.Ltd.,Chongqing 400800,China)

机构地区：[1]重庆理工大学材料科学与工程学院,重庆400054 [2]重庆材料研究院有限公司,重庆400707 [3]重庆中镭科技有限公司,重庆400800

出　　处：《金属学报》2024年第7期881-889,共9页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目No.52274374;中国博士后科学基金项目No.2021M703592;重庆市博士后研究(一等)资助项目No.2021XM1022;重庆市教育委员会科学技术研究计划青年项目No.KJQN202101141;重庆理工大学校级研究生创新项目No.gzlcx20222004。

摘　　要：为揭示双峰分离非基面织构AZ31镁合金板材预变形后的室温变形行为及微观组织演化规律,对该板材施加压下量5%的深冷轧制预变形,结合室温单轴拉伸和微观组织表征实验,研究预变形对制备板材力学行为及微观组织演变的影响。结果表明,沿轧制方向(RD)试样的初始屈服强度和断裂延伸率较未预变形试样分别提升212.5%和降低56.9%。沿板材横向(TD)试样的初始屈服强度和断裂延伸率较未预变形试样分别降低6.7%和提升37.9%。不同方向试样初始屈服强度的差异主要是由于TD试样中TD织构组分所对应的晶粒比RD试样中双峰分离非基面织构组分所对应的晶粒更容易激活基面滑移。断裂延伸率的差异主要是由于在RD试样中,{1012}拉伸孪晶的扩张受到抑制,会较早出现{1011}压缩孪晶,而在TD试样中,{1012}拉伸孪晶可以有效扩张,且后期出现一定数量的{1011}-{1012}双孪晶来承载/协调塑性应变。An AZ31 Mg alloy sheet with bimodal non-basal texture exhibits good formability at room temperature.However,its initial yield stress(YS)is relatively low during uniaxial tension along the rolling direction(RD)at room temperature,which limits its potential for further application.Recent studies have demonstrated that introducing{1012}extension twin(ET)through predeformation can improve the mechanical properties of Mg alloy sheets with a basal texture at room temperature.However,the predeformation process for Mg alloy sheets with non-basal texture has rarely been investigated,along with their subsequent plastic deformation behavior at room temperature.Therefore,to investigate the room temperature deformation behavior and microstructure evolution of an AZ31 Mg alloy sheet with bimodal non-basal texture after predeformation,this work exerted a 5%thickness reduction on the sheet via cryogenic rolling.Then uniaxial tension experiments at room temperature and microstructure characterization experiments were conducted to illuminate the effect of predeformation on the mechanical behavior and microstructure evolution of the fabricated sheet.The findings indicate that when loaded along the RD,the YS and fracture elongation(FE)of the predeformed sample are 212.5%larger and 56.9%smaller than those of the non-predeformed sample.When loaded along the transverse direction(TD),the YS and FE of the predeformed sample are 6.7%smaller and 37.9%larger than those of the non-predeformed sample.The difference in YS in the predeformed samples is primarily attributed to easier activation of basalslip in grains with a TD texture component in the TD sample than in grains with a bimodal non-basal texture component in the RD sample.The difference in FE in the predeformed samples is due to the inhibition of the expansion of preexsiting{1012}ETs in the RD sample,resulting in the early occurrence of{1011}compression twins(CTs).In comparison,the expansion of preexsiting{101ˉ2}ETs can be effectively performed in the TD sample.Additionally,some{10

关 键 词：AZ31镁合金 双峰分离非基面织构 预变形 微观组织演化 塑性变形机制 

分 类 号：TG146.22[一般工业技术—材料科学与工程]