( 哈爾濱工業(yè)大學 現(xiàn)代焊接生產(chǎn)技術國家重點實驗室, 哈爾濱 150001)
摘 要: 利用OM, SEM, XRD, TEM和顯微硬度等方法對電子束焊接Ti3Al+高鈮金屬間化合物接頭區(qū)域的顯微組織特征進行了分析。結果發(fā)現(xiàn)： 焊縫區(qū)域組織主要為有序亞穩(wěn)態(tài)殘余β相(B2相)， 其結晶形態(tài)為胞狀束晶， 焊縫區(qū)域存在一定程度的層狀偏析；熱影響區(qū)晶粒長大明顯， 晶粒的多邊化過程不充分； 熔合區(qū)和熱影響區(qū)的顯微硬度顯著高于母材， 焊縫中心區(qū)在整個焊縫部分硬度最低。
關鍵字: 電子束焊接； 鈦鋁合金； 金屬間化合物； 組織演化
alloy electron beam welding joints
HE Jing-shan, ZHANG Bing-gang
（ 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
