界面微观组织的影响
(1. 哈尔滨工业大学 现代焊接技术国家重点实验室， 哈尔滨 150001;
2. 北京矿冶研究总院, 北京 100001)
摘 要: 研究了Ti3Al基合金真空钎焊及接头组织性能；分析了不同钎料对接头界面组织和剪切强度的影响， 初步优选了钎料， 优化了钎焊连接规范参数； 利用电子探针、 扫描电镜和X射线衍射等方法对接头进行了定性和定量分析。 结果表明： 采用NiCrSiB钎料连接时， 在界面处有金属间化合物TiAl3、 AlNi2Ti和Ni基固溶体生成， TiAl3和AlNi2Ti的生成降低了接头的剪切强度；采用TiZrNiCu钎料连接时， 在界面处有金属间化合物Ti2Ni、 Ti(Cu,Al)2和Ti基固溶体生成， Ti2Ni和Ti(Cu,Al)2的形成降低了接头的剪切强度；采用AgCuZn钎料连接时， 在界面处生成TiCu、 Ti(Cu,Al)2和Ag基固溶体， TiCu和Ti(Cu,Al)2 的生成是降低接头剪切强度的主要原因；采用CuP钎料连接时， 在界面处生成了Cu3P、 TiCu和Cu基固溶体， Cu3P和TiCu使接头的剪切强度降低； 对于NiCrSiB钎料， 当连接温度为1 373 K， 连接时间为5 min时， 接头的剪切强度最高为219.6 MPa； 对于TiZrNiCu钎料， 当连接温度为1 323K， 连接时间为5 min时， 接头的最高剪切强度为259.6 MPa； 对于AgCuZn钎料， 当连接温度为1 173 K， 连接时间为5 min时， 接头的最高剪切强度为125.4 MPa； 对于CuP钎料， 当连接温度为1 223 K， 连接时间为5 min时， 接头的最高剪切强度为98.6 MPa； 采用TiZrNiCu钎料连接Ti3Al可获得最大接头强度。
关键字: Ti3Al基合金；钎焊； 界面组织； 剪切强度
（ 1. State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology,
Harbin 150001, China;
2. Beijing General Research Institute of Mining and Metallurgy, Beijing 100001, China）
Abstract: The interfacial microstructure and properties of brazed joints of Ti3Al-based alloy were investigated. The effects of different brazing fillers on interfacial microstructure and shear strength were studied. And the optimum joining parameters were given. The brazed joints were qualitatively and quantitatively analyzed by means of EPMA, SEM and XRD. The results show that using brazing filler NiCrSiB, TiAl3, AlNi2Ti and Ni[s,s] are formed at the interface of joint, and the formation of Ti3Al and AlNi2Ti decreases the shear strength. Using brazing filler TiZrNiCu, Ti2Ni, Ti(Cu,Al)2 and Ti[s,s] are formed at the interface of joint, the formation of intermetallics Ti2Ni and Ti(Cu,Al)2 decreases the shear strength. Using brazing filler AgCuZn, TiCu, Ti(Cu,Al)2 and Ag[s,s] are formed, the shear strength of the joint is decreased because of the formation of TiCu and Ti(Cu,Al)2. Using brazing filler CuP, Cu3P, TiCu and Cu[s,s] are formed at the interface of the joint, the former two intermetallics decrease the shear strength. The analysis also indicates that using brazing filler NiCrSiB, the optimum brazing parameters for the joint are joining temperature T=1 373 K, joining time t=5 min, and the maximum shear strength is 219.6 MPa. To the brazing filler TiZrNiCu, the optimum parameters are temperature T=1 323 K, joining time t=5 min, and the maximum shear strength is 259.6 MPa. To the brazing filler AgCuZn, the optimum parameters are joining temperature T=1 173 K, joining time t=5 min, and the maximum shear strength is 125.4 MPa. To the brazing filler CuP, the optimum parameters are joining temperature T=1 223 K, joining time t=5 min, and the maximum shear strength is 98.6 MPa.
Key words: Ti3Al-based alloy; brazing; interfacial microstructure; shear strength
