纯钛板材室温拉伸塑性变形的各向异性

Anisotropy of Plastic Deformation of Pure Titanium Sheet During Tensile Test at Room Temperature

基于纯钛板材不同取向室温拉伸力学性能的各向异性,采用动态接触式引伸计对该板材的应变过程进行了全程采集试验,并依据试验结果分析讨论了该板材横纵向塑性变形阶段的各向异性。结果表明,纯钛板材横纵向力学性能呈现出一定的各向异性,纵向屈服强度较低,而抗拉强度及断后伸长率则略高;板材具有明显的屈服特性,其良好的塑性依赖于不均匀集中塑性变形阶段,横向所占比例较纵向更为明显;板材横纵向塑性变形阶段的显著差异,致使应变硬化过程及临界失稳点呈现明显的各向异性。

Based on the anisotropy of tensile mechanical properties of pure titanium sheets under different orientations at room temperature,the strain date are collected by means of dynamic contacting extensometer for the whole process in this paper.The anisotropy of sheet under transverse and rolling direction is analysised and discussed during plastic deformation process.The results show that the transverse and rolling direction mechanical properties of pure titanium sheets exhibit anisotropy,the rolling direction yield strength is lower,and the tensile strength and elongation after fracture are slightly higher.The sheet have obvious yield characteristics,the better plasticity is attributed to heterogeneous plastic deformation,the proportion of transverse is more obvious than that the rolling direction.Significant difference exists between transverse and rolling direction during plastic deformation stage,results in obvious anisotropy during strain hardening and critical bucking point.