CAJ | 학술논문

对AZ31镁合金热挤压棒材在室温下沿挤压方向分别进行了应变为3%、6%、10%的单向压缩实验。利用OM、XRD和EBSD等技术研究了不同压缩应变量下的显微组织、织构及应变硬化的演变特征。结果表明：具有{0002}纤维织构的热挤压态AZ31镁合金沿着挤出方向压缩时，产生显著的应变硬化效应。其塑性变形可大致分为3个阶段：初始阶段主要发生{1012}拉伸孪生，表现为较低的应变硬化速率和应变硬化速率的急剧减小；随着压缩应变量的增加，孪晶界逐渐扩展，直至部分晶粒发生完全孪生，基面织构强度逐渐增强；拉伸孪晶生长所造成的强{0002}基面织构是产生高应变硬化速率的主要原因；应变硬化速率第Ⅱ~Ⅲ阶段的转折点大致与拉伸孪晶的生长停滞相对应。▁
대AZ31미합금열제압봉재재실온하연제압방향분별진행료응변위3%、6%、10%적단향압축실험。이용OM、XRD화EBSD등기술연구료불동압축응변량하적현미조직、직구급응변경화적연변특정。결과표명：구유{0002}섬유직구적열제압태AZ31미합금연착제출방향압축시，산생현저적응변경화효응。기소성변형가대치분위3개계단：초시계단주요발생{1012}랍신련생，표현위교저적응변경화속솔화응변경화속솔적급극감소；수착압축응변량적증가，련정계축점확전，직지부분정립발생완전련생，기면직구강도축점증강；랍신련정생장소조성적강{0002}기면직구시산생고응변경화속솔적주요원인；응변경화속솔제Ⅱ~Ⅲ계단적전절점대치여랍신련정적생장정체상대응。▁
Uniaxial compression tests were carried out on an as-extruded AZ31 magnesium alloy along extrusion direction at the strain of 3%, 6% and 10%, respectively, at room temperature. The evolution of microstructures, textures and strain hardening behavior were examined by OM, XRD and EBSD. The results show that the present as-extruded magnesium alloy with {0002} fiber texture exhibits distinct three plastic deformation stages. {101▁2} tension twinning takes place at the first stage of the plastic deformation, which results in the low strain hardening rate and rapid decrease in strain hardening rate. With increasing the compressive strain, {101▁2} twin boundaries gradually extend until some grains are entirely consumed by the twinning extension, which results in the strong basal texture. The increasing high strain hardening rate are mainly attributed to the formation of strong basal texture. The deformation transition from stageⅡ to stageⅢ roughly corresponds to the stop of {101▁2} twin extending.