Ti_(50)Ni_(47)Fe_3合金的铸态及均匀化热处理显微组织  

Microstructure of as-cast and homogenized Ti_(50)Ni_(47)Fe_3 alloy

作　　者：康小宇[1] 李艳锋[1] 尹向前[1] 解浩峰[1] 米绪军[1] 

机构地区：[1]北京有色金属研究总院有色金属材料制备加工国家重点实验室,北京100088

出　　处：《金属热处理》2013年第6期23-26,共4页Heat Treatment of Metals

摘　　要：采用真空感应法熔炼制备了Ti50Ni47Fe3合金铸锭,对合金铸锭进行了均匀化热处理,运用金相显微镜,XRD,带有EDS的SEM等手段进行显微组织分析。结果表明,Ti50Ni47Fe3合金的铸态显微组织由内到外依次呈不规则胞状、柱状和细长等轴状,主要原因为冷却速度不同导致合金的晶粒形核和长大存在差异。均匀化热处理一定程度上能消除枝晶偏析,1000℃下均匀化12 h后,合金枝晶偏析和析出相显著减少。Ti50Ni47Fe3 shape memory alloy was prepared by vacuum induction melting, and then homogenized. Microstructure of the alloy was investigated by optical microscope, XRD and SEM equipped with EDS. The results show that the microstructure of the as-cast alloy in sequence from inside to outside are in irregularly cellular, columnar and elongated-equiaxed structure. It is ascribed to the difference of crystal grain nucleation and growth by different cooling rate. The homogenization treatment can decrease interdendritic segregation and precipitated phases to a certain extent. After homogenized at 1000 ℃ for 12 h, the dendritic segregation and precipitation of the alloy decrease significantly.

关 键 词：Ti50Ni47Fe3合金 均匀化热处理 显微组织 枝晶偏析 

分 类 号：TG166.5[金属学及工艺—热处理]