TC4合金热变形特性及变形参数对组织和性能的影响

Influence of TC4 Alloy Deformation Characteristics and Parameters on Microstructure and Mechanical Property

采用等温压缩实验法,研究了TC4钛合金在800～1050℃温度范围和应变速率为0.005s-1～5s-1范围内的高温变形行为,分析了变形参数对锻件显微组织及力学性能的影响。结果表明,800～950℃区间内变形,合金的变形激活能为602.55kJ/mol,流变软化行为明显,具有显著的动态再结晶特征;1000～1050℃区间内变形,变形激活能为193.72kJ/mol,表现为动态回复特征。970℃以下锻造成形,合金的显微组织为双态组织,锻件具有较好的强度和塑性匹配,且变形速率降低有利于增加组织中等轴状α相含量,提高锻件的塑性。

High temperature deformation characteristics of TC4 alloy are investigated within tem- perature range of 800-1050℃ and strain rate range of 0.005s^-1-5s^-1 with isothermal compression test, and the influence of deformation parameters on the microstructure and mechanical properties are analyzed, The results show that the deformation mechanisms of TC4 alloy exhibit dy- namic recrystallization with deformation activation energy value 602.55kJ/mol within temperature range 800-950℃, while deformation within temperature 1000-1050℃ , the alloy exhibit dynamic recovery with deformation activa- tion energy value 193.72k J/tool. The integrated matching of strength and plasticity can be obtained for the forgings with duplex microstructure, and the plasticity increaseds with decreasing deformation rate due to the increased equi- axed ct phase volume fraction.