Ti-25Al-14Nb-2Mo-1Fe合金热压缩变形流变应力行为与微观组织演变的研究  

Research on Flow Stress Behavior and Microstructure Evolution During Hot Compression of Ti-25Al-14Nb-2Mo-1Fe Alloy

作　　者：程军[1,2] 毛勇[2] 于振涛[1] 牛金龙[1] 余森[1] 麻西群[1] 刘少辉[1] 牛红志[1] 

机构地区：[1]西北有色金属研究院,陕西西安710016 [2]云南大学,云南昆明650091

出　　处：《钛工业进展》2014年第3期26-29,共4页Titanium Industry Progress

基　　金：云南省应用基础研究面上项目(2008CD075)

摘　　要：在Gleeble-3500热模拟试验机上对Ti-25Al-14Nb-2Mo-1Fe合金进行了等温恒应变速率压缩试验，研究了在变形温度为950-1100℃，应变速率为0.001-1 s-1，最大变形程度为50%的条件下合金的热压缩变形流变应力行为与微观组织演变。结果表明：Ti-25Al-14Nb-2Mo-1Fe合金的流变应力对变形温度和应变速率均较为敏感，其流变应力曲线具有应力峰值、流变软化和稳态流变的特征。在变形温度为950℃，应变速率为0.001-0.1 s-1的条件下，Ti-25Al-14Nb-2Mo-1Fe合金的热变形特性为片层组织球化，其热变形机制可用晶界分离球化模型进行解释说明；在变形温度为1000-1100℃，应变速率为1 s-1的条件下，材料只发生了动态回复现象；在变形温度为1050-1100℃，应变速率为0.001-0.1 s-1的条件下，材料发生了动态再结晶现象。The flow stress behavior and microstructure evolution of Ti-25 Al-14 Nb-2 Mo-1 Fe alloy was investigated at deformation temperatures between 950 ℃ and 1 100 ℃ with strain rate between 0. 001 s-1 and 1 s-1 ,and the heigh-test reduction of 50% by using isothermal compression testing on Gleeble-3500 simulator. The results show that the flow stress of the alloy is sensitive to the variation of deformation temperature and strain rate. The stress-strain curves exhibit a peak flow stress,flow softening and steady state flow behavior. The hot deformation microstructure feature of Ti-25Al-14Nb-2Mo-1Fe alloy deformed at 950 ℃,0. 001-0. 1 s-1 is lamellar globularization. The dominant deforma-tion mechanism is illustrated by the models of the splitting of grain boundaries. The hot deformation microstructure feature of the alloy deformed at 1 s-1 ,1 000 -1 100 ℃ is dynamic recovery. The hot deformation microstructure feature of the alloy deformed at 1 050-1 100 ℃,0. 001-0. 1 s-1 is dynamic recrystallization.

关 键 词：Ti2 AlNb基合金 热变形 流变应力 组织演变 

分 类 号：TG146.23[一般工业技术—材料科学与工程]