铸态Ti-44Al-4Nb-(Mo,Cr,B)合金的热变形行为及热加工图  

Hot Deformation Behavior and Thermal Processing Map of As-cast Ti-44Al-4Nb-(Mo,Cr,B) Alloy

作　　者：朱凯 冯艾寒[1] 曲寿江[1] 沈军[1,2] ZHU Kai;FENG Aihan;QU Shoujiang;SHEN Jun(School of Materials Science and Engineering, Tongji University,Shanghai 201800,China;College of Machatronics and Control Engineering, Shenzhen University,Shenzhen 518061,China)

机构地区：[1]同济大学材料科学与工程学院,上海201800 [2]深圳大学机电与控制工程学院,广东深圳518061

出　　处：《有色金属工程》2019年第9期34-39,共6页Nonferrous Metals Engineering

基　　金：国家自然科学基金资助项目(U1302275)~~

摘　　要：利用Gleeble热模拟机研究了铸态Ti-44Al-4Nb-(Mo,Cr,B)合金在1050~1200℃、0.005~0.5s-1下的热变形行为,并基于所得的真应力-真应变曲线绘制了热加工图。另外,通过透射电子显微镜(TEM)研究了片层和γ相的变形机制。结果表明,该合金是典型的应变速率和温度敏感材料,它的热加工性能较好,在1100、1150℃温度下的低应变速率区域以及1200℃温度下高应变速率区域比较适合热加工。再结晶是流变软化的主要原因,较高的变形温度和较低应变速率有利于再结晶晶粒的进行。片层结构的变形机制为片层扭折,而γ相的主要变形机制为位错滑移和变形孪晶。The hot deformation behavior of as-cast Ti-44Al-4Nb-(Mo, Cr, B) alloy at 1 050-1 200 ℃ and 0.005-0.5 s -1 was investigated by Gleeble thermal simulator. The processing map is plotted on the basis of the true strain-stress curves. In addition, the deformation mechanism of the lamellae and γ phase was investigated by transmission electron microscopy (TEM). The results show that the alloy is a typical strain rate and temperature sensitive material, and it has good hot workability. It is suitable for processing in the low strain rate region of 1 100-1 150 ℃ and the high strain rate region of 1 200 ℃. Recrystallization is the main cause of rheological softening mechanism during hot deformation, and higher deformation temperature and lower strain rate are beneficial to the progress of recrystallization grains. The deformation mechanism of the lamellar structure is kinking, and the main deformation mechanism of the γ phase is dislocation slip and deformation twinning.

关 键 词：TIAL基合金 热压缩 动态再结晶 变形机制 

分 类 号：TG146.23[一般工业技术—材料科学与工程]