( 哈尔滨工业大学 现代焊接生产技术国家重点实验室, 哈尔滨 150001)
摘 要: 利用OM, SEM, XRD, TEM和显微硬度等方法对电子束焊接Ti3Al+高铌金属间化合物接头区域的显微组织特征进行了分析。结果发现： 焊缝区域组织主要为有序亚稳态残余β相(B2相)， 其结晶形态为胞状束晶， 焊缝区域存在一定程度的层状偏析；热影响区晶粒长大明显， 晶粒的多边化过程不充分； 熔合区和热影响区的显微硬度显著高于母材， 焊缝中心区在整个焊缝部分硬度最低。
关键字: 电子束焊接； 钛铝合金； 金属间化合物； 组织演化
alloy electron beam welding joints
（ National Key Laboratory of Advanced Welding Production Technology,Harbin Institute of Technology, Harbin 150001， China）
Abstract: Microstructure evolution characterization of high Nb containing Ti3Al-based intermetallic compound with electron beam welds was studied by means of OM, SEM, XRD, TEM and microhardness analysis. The results indicate that the microstructure of weld metal made with electron beam under the welding conditions employed is predominantly metastable β(B2). The crystallizing morphology of fusion zone is cellular structure with stratified segregation. There exists grain coarsening in HAZ for insufficient polygonization. Both FZ and HAZ have higher microhardness than the base metal has, and microhardness in fusion centre zone is the lowest.
Key words: electron beam welding; titanium aluminium alloy; intermetallic compound; microstructure evolution
