TA11钛合金片状组织缺口拉伸行为及机理研究

Study on the notch tensile behavior and mechanism of TA11 titanium alloy with lamellar structure

本文对比研究了缺口角度(30°,45°,90°)对TA11钛合金片状组织的拉伸性能及断裂行为的影响规律。基于真应力-真应变曲线及OM、SEM分析,获得如下结论:随缺口角度增加,TA11钛合金拉伸承载能力下降,塑性变形能力最受影响;α集束为TA11钛合金的变形单元及断裂单元,当裂纹沿着某个α集束运动至其与另一个α集束的界面时,由于取向的改变,裂纹发生偏转;整体上,缺口角度越小,缺口根部应力三轴度越低,裂纹扩展路径越崎岖,因此可获得大的非均匀塑性变形量。

In this paper,the effect of notch angle（30°,45°,90°）on the tensile properties and the fracture behavior of TAll titanium alloy have been studied.Based on the analyses of true stress-true strain curves,OM and SEM photos,some conclusions can be drawn：with increasing notch angle,the bearing ability of TA11 alloy decreases,which is more obvious for plasticity;α colony is the deformation and fracture element of TA11 alloy,the crack can deflect at the interface of two adjacent α colonies due to the change of orientation ;generally speaking,the less notch angle is,the less the stress triaxiality at the notch tip,this leads to more tortuous crack propagation path,which results in bigger nonuniform plastic deformation.