Si_3N_4/(Cu,Nb)/Ni/Inconel600高温合金部分液相扩散连接接头的组织与力学性能

The mechanical characteristics and microstructure of the partial liquid phase diffusing bonding joint of Si_3N_4/(Cu,Nb)/Ni/Inconel 600 high temperature alloy

为了在较低的连接温度、连接压力和连接时间下获得高温稳定性好的陶瓷/金属接头,通过设计非对称中间层(Cu,Nb)/Ni,在连接温度为1403 K/1373 K,连接时间为50 min,连接压力为7.5 MPa,冷却速度为10 K/min的工艺条件下,采用真空扩散连接设备,进行了Si3N4/Inconel600高温合金接头的部分液相扩散连接(partial liquid phase dif-fusion bonding,PLPDB).接头的强度通过剪切试验评价,接头组织形态采用扫描电子显微镜(SEM)进行了观察和分析.实验结果表明,Cu,Nb配比、(Cu,Nb)层的厚度和连接温度影响接头的组织形态、强度与断裂.在连接温度为1403 K时,Cu,Nb配比增加,接头中的孔洞缺陷减小,接头强度提高,断裂位置从陶瓷/中间层界面向陶瓷转变.当连接温度为1403 K,Cu,Nb配比为10,(Cu,Nb)层厚度不超过0.2 mm时,随着(Cu,Nb)层厚度的增加,接头强度提高.当连接温度从1403 K降到1373 K时,接头强度明显提高.

In order to obtain a ceramic/metal joint with excellent high temperature properties under lower bonding temperature, less bonding pressure and short bonding time, the partial liquid phase diffusion bonding （PLPDB） of Si3 N,/Inconel 600 has been conducted in a vacuum diffusing bonding machine through asymmetric interlayer design. The bonding time, pressure and cooling velocity were 50 min, 7.5 MPa and 10 K/min, respectively, and the bonding temperature varied from 1373 K to 1403 K. While the strength of the joint was evaluated by shear test, the microstructure of the joint was observed and analyzed by scanning electron microscope. Results show that the thickness of （Nb, Cu） layer, the ratio of Cu to Nb and bonding temperature affect the microstructure, strength and fracture of the joint. When the bonding temperature was 1403 K, the increase of Cu to Nb ratio resulted in the reduction of porosities in the joint, increase of joint strength and change of the fracture location from the interface between ceramic and interlayer to ceramic. When the bonding temperature is 1403 K, the ratio of Cu to Nb is 10 and the thickness of （Cu,Nb） layer is less than 0.2 mm, the strength of the joint is raised while the thickness of （Cu, Nb） layer increased. The strength Of the joint rose obviously when the bonding temperature fell from 1403 K to 1373 K.