基于摩擦修正的 TA15 钛合金热变形行为及加工图

目的采用Gleeble-3500热模拟实验机,研究TA15钛合金在变形温度为900~1050℃、应变速率为0.01~1 s-1条件下的热压缩流变行为及变形组织。方法采用一种简单有效的方法修正了TA15钛合金热压缩实验中摩擦引起的误差;计算出了TA15钛合金的应力指数和热变形激活能,建立了含有Z参数的双曲正弦函数形式本构方程;基于Murty准则,建立了其加工图。结果TA15钛合金的热压缩流变行为可采用含有Z参数的双曲正弦函数形式本构方程来描述,其平均变形激活能为625.884 kJ/mol;通过分析热加工图,确定了最优热变形工艺参数为:T=950℃,ε=0.01 s-1。结论研究结果可为TA15钛合金的塑性变形数值模拟提供基础,对合理制定热加工工艺具有重要指导意义。

Hot Deformation Behavior and Processing Map of TA15 Titanium Alloy Based on Friction Correction

Objective The flow stress behavior and deformation microstructure of hot compressed TA15 titanium alloy were investigated by hot compression tests on Gleeble- 3500 thermal simulation machine in the strain rate range of 0. 01 ~1 s- 1and temperature range of 900 ~ 1050 ℃. Methods A simple and effective correction method was adopted to reduce the errors caused by friction during the compression process of TA15 titanium alloy. The stress exponent and hot deformation activation energy at elevated temperature were calculated,and the constitutive equation including Z parameter was established on the basis of hyperbolic sine function model. Based on Murty criteria the processing map was obtained. Results The hot deformation behavior of TA15 titanium alloy could be described by a constitutive equation in hyperbolic sine function including Z parameter and the average hot deformation activation energy was 625. 884 kJ /mol. The optimal thermal deformation process parameters were T = 950 ℃,ε = 0. 01 s- 1by analyzing the processing map. Conclusion The results pro-vided a basis for numerical simulation of plastic deformation and an important guiding significance for the rational development of thermal processing of TA15 titanium alloy.