(1. 南昌航空大学 航空制造工程学院，南昌 330063；
2. 南昌航空大学 材料科学与工程学院，南昌330063)
摘 要: 采用Thermecmaster-Z型热加工模拟试验机对Ti60合金进行等温恒应变速率压缩实验，通过分析流动应力-应变曲线的流动特征，计算加工硬化率，观察变形微观组织，并结合变形激活能的计算，研究该合金在变形温度为850~950 ℃、应变速率为0.001~10 s-1、真应变为0.51热变形条件下的软化机制。结果表明：Ti60合金在低应变速率(0.001~0.1 s-1)和高应变速率(1~10 s-1)区间流动应力-应变曲线分别呈现流动稳态型和流动软化型两种；加工硬化率曲线呈现无拐点特征；变形微观组织为动态回复组织，未出现动态再结晶现象；变形激活能在低应变速率区间和高应变速率区间分别为484.35 kJ/mol和500.76 kJ/mol，两者相差不大。综合这些结果可以判定，Ti60合金的软化机制以动态回复为主。
关键字: Ti60合金；加工硬化率；变形微观组织；变形激活能；软化机制
（1. School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China;
2. School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China）
Abstract:The isothermal compression tests of Ti60 alloy were conducted on the Thermecmaster-Z thermal simulator, through analyzing the flow stress-strain curve characteristics, calculating work hardening rate, observing deformation microstructure of alloy and the deformation activation energy, the softening mechanism is that deformation temperature of 850-950 ℃, the strain rate of 0.001-10 s-1 and true strain of 0.51. The results show that flow stress-strain curve of Ti60 alloy presents the flow steady state under low stain rate (0.001-0.1 s-1) and flow softening state under high stain rate (1-10 s-1), respectively. The curve of work hardening rate shows no inflection point. The microstructure of deformation is dynamic recovery microstructure without dynamic recrystallization. The activation energy of deformation is 484.35 kJ/mol under low stain rate and 500.76 kJ/mol under high stain rate, with little difference between them. Comprehensively based on these results, it can be concluded that the softening mechanism of Ti60 alloy is mainly dynamic recovery.
Key words: Ti60 alloy; work hardening rate; deformation microstructure; deformation activation energy; softening mechanism
