TC17钛合金表面残余应力的点阵式维氏压痕测试

Lattice Vickers Indentation Testing of Residual Stress on Surface of TC17 Titanium Alloy

采用点阵式维氏压痕测试方法得到TC17钛合金表面12个测试点的载荷-深度曲线;通过等效材料维氏压痕模型计算合金表面12个测试点的双向残余应力和单向残余应力,将残余应力值代入ANSYS 19.2有限元分析软件中得到载荷-深度曲线,并进行试验验证。结果表明:试验得到表面不同测试点的应力均为残余拉应力;采用有限元方法模拟得到双向残余应力和单向残余应力下的载荷-深度曲线与试验结果吻合较好,载荷-深度曲线的加载曲率的相对误差均小于1.5%,等效材料维氏压痕模型可以准确地预测合金表层单向残余应力和双向残余应力分布。

The load-depth curves of 12 test points on the surface of TC17 titanium alloy were obtained by lattice Vickers indentation testing method.The bidirectional and unidirectional residual stresses of 12 test points on the alloy surface were calculated by equivalent material Vickers indentation model.The load-depth curves were obtained by substituting the residual stress values into the finite element analysis software ANSYS 19.2,and were verified by tests.The results show that the stresses at different test points on the surface were all residual tensile stresses by testing.The load-depth curves under both the bidirectional residual stress and the unidirectional residual stress simulated by finite element method were in good agreement with test results,and the relative errors of the loading curvature of the load-depth curves were less than 1.5%,which indicated that the equivalent material Vickers indentation model could accurately predict the distribution of unidirectional residual stress and bidirectional residual stress on the alloy surface layer.