摘要
基于三向取样拉伸实验研究了挤压态AZ31镁合金室温拉伸各向异性力学行为,从微观变形机制的角度分析了挤压态镁合金宏观拉伸各向异性产生的机理.结果表明,挤压态镁合金三向取样拉伸塑性变形初期,主导变形机制虽然都是基面滑移,但是基面滑移开启所对应的施密特(Schmid)因子不同,得到同样的分切应力所需要施加的宏观外界应力就会不同,最终导致了三向取样拉伸屈服强度各向异性;随着变形的深入,0°拉伸主导变形机制转变为柱面滑移,而45°和90°拉伸主导变形机制仍然是基面滑移,这就导致了后期变形过程中0°拉伸流变应力远高于45°和90°拉伸过程;总而言之,挤压态镁合金初始丝织构分布,决定了其沿不同方向拉伸变形时不同机制导致的相对变形量和变形抗力各不相同,引起了宏观拉伸力学性能的各向异性.
Study the mechanical behavior of tensile anisotropic in extruded AZ31 magnesium alloy based on three-way tensile testing.at room temperature,the mechanism of macroscopic tensile anisotropy in extruded magnesium was analyzed from the perspective of the microscopic deformation mechanism.The results show that,basal slip is the dominant deformation mechanism in the early stage of plastic deformation along three tensile directions in extruded magnesium alloy,but the corresponding Schmid factor of basal slip is different which results that obtaining the same shear stress needs to be applied to different macroscopic external stress,which eventually leads to the anisotropy of yield strength in the three-way sampling tensile.With the increase of strain,the dominant deformation mechanism of 0°tensile becomes prismatic slip,while 45°and 90°tensile deformation mechanism is still the dominant basal slip,which leads to the flow stress of 0°tensile is much higher than 45 and 90 progress in the late stage of deformation.All in all,fiber texture of extruded magnesium alloy determines that the relative activity deformation and the deformation resistance are different when the tensile deformation is in different directions,which leads to the anisotropy of the macroscopic tensile mechanical properties.
作者
林金保
王心怡
任伟杰
李倩
LIN Jin-bao;WANG Xin-yi;REN Wei-jie;LI Qian(School of Applied Science,Taiyuan University of Science and Technology,Taiyuan 030024,China)
出处
《中北大学学报（自然科学版）》
CAS
2018年第4期479-482,共4页
Journal of North University of China(Natural Science Edition)
基金
国家自然科学基金联合基金资助项目(51574171)
山西省自然科学基金资助项目(201601D011012
2015011002)
关键词
AZ31镁合金
各向异性
变形机制
孪生
AZ31 magnesium alloy
anisotropy
deformation mechanism
twinning
