(1. 南昌航空大學 航空制造工程學院，南昌 330063；
2. 南昌航空大學 材料科學與工程學院，南昌330063)
摘 要: 采用Thermecmaster-Z型熱加工模擬試驗機對Ti60合金進行等溫恒應變速率壓縮實驗，通過分析流動應力-應變曲線的流動特征，計算加工硬化率，觀察變形微觀組織，并結合變形激活能的計算，研究該合金在變形溫度為850~950 ℃、應變速率為0.001~10 s-1、真應變?yōu)?.51熱變形條件下的軟化機制。結果表明：Ti60合金在低應變速率(0.001~0.1 s-1)和高應變速率(1~10 s-1)區(qū)間流動應力-應變曲線分別呈現(xiàn)流動穩(wěn)態(tài)型和流動軟化型兩種；加工硬化率曲線呈現(xiàn)無拐點特征；變形微觀組織為動態(tài)回復組織，未出現(xiàn)動態(tài)再結晶現(xiàn)象；變形激活能在低應變速率區(qū)間和高應變速率區(qū)間分別為484.35 kJ/mol和500.76 kJ/mol，兩者相差不大。綜合這些結果可以判定，Ti60合金的軟化機制以動態(tài)回復為主。
關鍵字: Ti60合金；加工硬化率；變形微觀組織；變形激活能；軟化機制
（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
