采用Ti/Ag-Cu/Cu中间层钎焊连接Si3N4陶瓷和TiAl合金的界面结构及性能

采用Ti/Ag-Cu/Cu中间层实现了Si₃N₄陶瓷与TiAl合金的钎焊连接，获得了良好的接头.利用SEM，EDS等微观手段，分析了接头界面结构和元素分布情况.结果表明，Si₃N₄陶瓷/Ti/Ag-Cu/Cu/TiAl典型界面微观结构可能为:Si₃N₄/TiN/Ti-Si/Cu-Ti+Ag（s，s）+Cu（s，s）/AlCuTi/TiAl.在连接温度1 133 K、保温时间30 min、接头压力0.040 MPa时，接头四点弯曲强度达到最大值170 MPa.

Interfacial structure and properties of Si3N4 ceramic and TiAl alloys brazed with Ti/Ag-Cu/Cu interlayers

The Si₃N₄ ceramics was brazed to TiAl alloys with Ti/Ag-Cu/Cu as the interlays, and a good joint was obtained. The interfacial microstructure of the joint and the elements were analyzed by scanning electron microscope (SEM) and energy dispersive spectrometer distribution (EDS). The results show that the typical interfacial microstructure of Si₃N₄/Ti/Ag-Cu/Cu/TiAl may be Si₃N₄/TiN/Ti-Si/Cu-Ti+Ag(s,s)+Cu(s,s)/AlCuTi/TiAl. The influences of brazing temperature, holding time and the pressure of the joint on the four-point bending strength of the joint were researched by using controlling variables method. The four-point bending strength of the joint reaches the maximum of 170 MPa when the brazing temperature, holding time and the pressure of the joint are 1 133 K, 30 min and 0.040 MPa, respectively.