(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: 在1173~1373K、 0.3~5.4ks的接合条件下对TiAl金属间化合物与40Cr钢进行了真空扩散连接。 采用扫描电镜(SEM)、 电子探针微区成分分析(EPMA)、 X射线衍射分析(XRD)等方法确定了反应相的种类和界面结构。 研究结果表明，在1373K的接合温度下， TiAl/40Cr接头生成了TiC, Ti3Al, FeAl和FeAl24种反应相，形成了3个反应层， 界面结构为TiAl/Ti3Al+FeAl+FeAl2/TiC/脱碳层/40Cr钢。 界面总反应层的厚度随接合温度和接合时间按抛物线方程成长， 成长的活化能Q为211.9kJ/mol, 成长常数k0为4.6×10－5m2/s。 当脆性反应层厚度为3μm时， TiAl/40Cr钢接头的室温拉伸强度达到183MPa的最大值。
关键字: TiAl； 扩散连接； 界面结构； 反应机理；接头强度
（National Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001, China）
Abstract:TiAl intermetallic compound was joined to 40Cr steel by diffusion bonding at the temperature range of 1173~1373K for 0.3~5.4ks in vacuum. Reaction phases and interface structures were investigated by SEM, EPMA analysis and XRD diffraction method. At the bonding temperature of 1373K, four phases of TiC, Ti3Al, FeAl and FeAl2 were established and three layers were formed in the TiAl/40Cr joint, the interface structures were observed as TiAl/ Ti3Al+FeAl+FeAl2/TiC/decarbonized layer/40Cr steel. The total reaction layer grows with the joining time following the parabolic law, the activation energy Q and rate constants k0 for the growth are 211.9kJ/mol and 4.6×10－5m2/s respectively. At the 0.3μm reaction layer thickness of TiC+Ti3Al+FeAl+FeAl2, the maximum strength of the TiAl/40Cr joint is up to 183MPa at room temperature.
Key words: TiAl; diffusion bonding; interface structure; reaction mechanism; joining strength
