摘要
采用等温压缩实验研究了具有马氏体组织的TC11合金在两相区的变形行为及微观组织演变规律。等温压缩实验在Gleeble3500热模拟实验机上进行,其中变形温度为920～980℃,应变速率为0.1～10s-1,变形量为70%。基于动态材料模型(DMM),建立了具有马氏体组织的TC11合金两相区变形的热加工图。在低温(<940℃)区和高温(>960℃)高应变速率(>1s-1)区域存在失稳现象,主要表现为低温时的表面开裂和高应变速率区的绝热剪切带;在塑性加工安全区域,分别对应着片层扭折和片层球化的组织机制,其中变形量70%时应变速率敏感因子在980℃,0.1s-1时取得峰值为0.73,此时可得到完全球化的细晶组织(等轴α尺寸约为0.7μm)。具有马氏体组织的TC11合金两相区变形时,为避免缺陷并得到细的等轴组织,合适的加工工艺为温度:950～980℃,应变速率0.1～1s-1。
The effect of processing parameters formation behavior and microstructure evolution on deduring sub-transus deformation of TC 11 alloy with martensite microstructure was studied using isothermal hot compression tests. Testing was conducted on Gleeble 3500 hot simulator at strain rates of 0.1 - 10 s^-1, temperature range 920 - 980 ℃ and height reductions of 70%. The processing maps for martensite microstructures were constructed based on dynamic materials model （DMM）. In the working regions of temperatures lower than 940 ℃ or higher than 960℃ and strain rate higher than 1 s^-1 flow instability including surface cracking and adiabatic shear band （ASB） were observed. In safe regions of plastic working processing, deformed microstructures showed lamella kinking and dynamic globularization. After imposing 70% deformation on the alloy, the peak strain rate sensitivity in- dex of about 0.73 at 980 %, 0.1 s^-1 was observed, that was corresponding to fully fined globularized microstructure （the grain size of globularized a phase was about 0.7 μm）. To avoid defects and realize microstructure control, the appropriate processing parameters were 950- 980 ℃, 0.1 - 1 s^-1 for sub-transus deformation of TC 11 alloy with martensite microstructure.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2008年第6期698-704,共7页
Chinese Journal of Rare Metals
关键词
TC11钛合金
等温压缩
组织机制
工艺优化
TC11 alloy
isothermal compression
microstructure mechanism
process optimization
