具有马氏体组织的TC11合金两相区变形的组织机制及工艺优化  

Microstructure Mechanism and Processing Optimization during Sub-Transus Deformation of TC11 Alloy with Martensite Microstructure

作　　者：宋鸿武[1] 程明[1] 张士宏[1] 门菲[2] 王忠堂[2] 

机构地区：[1]中国科学院金属研究所,辽宁沈阳110016 [2]沈阳理工大学材料科学与工程学院,辽宁沈阳110168

出　　处：《稀有金属》2008年第6期698-704,共7页Chinese Journal of Rare Metals

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.

关 键 词：TC11钛合金 等温压缩 组织机制 工艺优化 

分 类 号：TG146.2[一般工业技术—材料科学与工程]