第41卷第3期陕西科技大学学报Vol.41No.32023年6月JournalofShaanxiUniversityofScience&TechnologyJun.2023*文章编号:2096-398X(2023)03-0138-09(α2+γ)双态细晶高铌TiAl合金的热变形行为及其机制杨光1,左俊娴1,杨肖肖2,韩松松1,白文鹏1,李誉之1(1.陕西科技大学机电工程学院,陕西西安710021;2.西安优耐特容器制造有限公司,陕西西安710201)摘要:在Gleeble-1500D热模拟试验机上对(α2+γ)双态细晶高铌TiAl合金进行热压缩实验,研究了其热变形行为和变形机制.结果表明:不同变形条件下的应力-应变曲线均呈现“加工硬化-动态软化”的特征,并且峰值应力随着变形温度的升高和应变速率的降低逐渐减小.采用幂率方程对不同工艺参数下的应力指数n和表观激活能Q进行了计算,结合显微组织表征分析了该合金的变形机制.在低温高应变速率下合金的变形由位错蠕变机制主导,在高温低应变速率下合金的变形受位错蠕变和晶界滑动机制共同控制.关键词:高铌TiAl合金;热变形行为;显微组织;变形机制中图分类号:TG113.12文献标志码:AHotdeformationbehaviorsandmechanismsofhighNbcontainingTiAlalloyswithrefined(α2+γ)duplexmicrostructureYANGGuang1,ZUOJun-xian1,YANGXiao-xiao2,HANSong-song1,BAIWen-peng1,LIYu-zhi1(1.CollegeofMechanicalandElectricalEngineering,ShaanxiUniversityofScience&Technology,Xi'an710021,China;2.Xi'anUnitedPressureVesselCo.,Ltd.,Xi'an710201,China)Abstract:Inthiswork,hotdeformationbehaviorsanddeformationmechanismsofhighNbcontainingTiAlalloyswithrefined(α2+γ)duplexmicrostructurewereinvestigatedbyhotcompressionexperimentsonGleeble-1500Dmachine.Resultsshowedthatthestress-straincurvesunderdifferentdeformationconditionspresentedacharacteristicof″workhardening-dynamicsoftening″,andpeakstressdecreasedwiththeincreaseofdeformationtemperatureanddecreaseofstrainrate.ThestressindexnandapparentactivationenergyQunderdiffer-entdeformationconditionswerecalculatedbypowerrateequation,anddeformationmecha-nismsofthealloyswereanalyzedcombinedwithmicrostructurecharacterization.Deformationofthealloysunderlowtemperatureandhighstrainratewasdominatedbydislocationcreepmechanism,whilethedeformationunderhightemperatureandlowstrainratewascontrolledbybothdislocationcreepandgrainbou...
