(1. 南昌航空大学 轻合金加工科学与技术国防重点学科实验室，南昌 330036；
2. 航空工业西安飞机工业(集团)有限责任公司，西安 710089)
摘 要: 利用等温压缩实验研究了β转变组织TA15钛合金在变形温度750~950 ℃、应变速率0.001~10 s-1范围内的流动软化行为，定量分析了变形热效应和微观组织演变对流动软化行为的影响。结果表明：变形热效应是β转变组织TA15钛合金流动软化的重要机制，变形热软化程度随着变形温度的下降和应变速率的增大而增强，最高占到总流动软化程度的48.2%；动态再结晶、动态回复和流动失稳缺陷等形式的微观组织演变是流动软化的主要机制。基于动态材料模型，利用应变速率敏感性指数预测了3种微观组织演化形式主导的软化区域，并通过微观组织观测进行了验证。
关键字: TA15钛合金；流动软化；变形热效应；微观组织演变
（1. National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University, Nanchang 330063, China;
2. Aviation Xi’an Aircraft Industry Croup Co., Ltd., Xi’an 710089, China）
Abstract:The flow softening of TA15 titanium alloy with beta transformed microstructure was investigated by means of hot compression tests performed at the temperature range of 750-950 ℃ and strain rate of 0.001-10 s-1. The effect of deformation temperature and strain rate on the flow softening and the flow softening mechanisms were examined. The thermal softening due to deformation heating is an important mechanism of flow softening. The degree of thermal softening increases with the decrease of deformation temperature and the increase of strain rate, and the maximum is 48.2% to the total flow softening degree. The microstructural evolution, including dynamic recrystallization, dynamic recovery and flow instability defects, is the main mechanism of flow softening. Three types of softening regions dominated by microstructure evolution were identified by strain rate sensitivity index based on the dynamic material model, and verified by microstructure observation.
Key words: TA15 titanium alloy; flow softening; deformation heating; microstructural evolution
