TA2拉压力学性能不对称性及应变速率敏感性

The Asymmetry of Tension-Compression Performances and strain rate sensitivity of TA2

摘要:

本文研究了不同应变速率下工业纯钛TA2室温拉伸和压缩力学行为，结果发现TA2具有明显的拉压屈服不对称性和拉压应变硬化不对称性；随着应变速率的增加，拉压不对称性有明显增加。采用电子背散射衍射（EBSD）技术分析了拉伸和压缩时TA2微观变形机制及微观组织演化规律，结果表明，TA2压缩时以孪晶变形机制为主，拉伸时以位错滑移为主；TA2微观变形行为的载荷敏感性导致了宏观力学性能的不对称性。

Abstract:

The behavior of commercially pure titanium (TA2) under tension and compression were investigated at different strain rates. Significant tension-compression asymmetry in yielding and strain hardening was observed. With the increment of deformation strain rate, the asymmetry of TA2 increased. The microscopic deformation mechanisms and microstructure evolutions of commercially pure titanium under tension and compression were analyzed using electron backscattered diffraction (EBSD) techniques. The results showed that the compressive deformation of commercially pure titanium was dominated by deformation twinning while the tensile deformation was dominated by the dislocations sliding. The macroscopic tension-compression asymmetry of commercially pure titanium was determined by load sensitivity of microscopic deformation behaviors.