C_f/SiC复合材料与Ti合金的AgCuTi-W复合钎焊

Joining of C_f/SiC Composite to Ti Alloy using AgCuTi-W Composite Filler Materials

本文利用AgCuTi-W复合钎料作中间层,在适当的工艺参数下真空钎焊Cf/SiC复合材料与Ti合金,利用SEM,EDS,XRD分析接头微观组织结构,利用剪切试验检测接头力学性能。研究结果表明:钎焊时,复合钎料中的Ti借助Cu-Ti液相与Cf/SiC复合材料反应,在Cf/SiC复合材料与连接层界面形成Ti3SiC2,Ti3Si和少量TiC化合物的混合反应层。复合钎料中的Cu与Ti合金中的Ti发生互扩散,在连接层与Ti合金界面形成不同成分的Cu-Ti化合物过渡层。钎焊后,形成W颗粒强化的致密复合连接层,W颗粒主要分布在Cu-Ti相中。W的加入缓解了接头的残余热应力,C/SiC/AgCuTi-W/TC4接头剪切强度明显高于C/SiC/AgCuTi/TC4接头。

Cf/SiC was successfully joined to Ti alloy with AgCuTi-W mixed powder by some suitable brazing parameters. Microstructures of the brazed joint were investigated by SEM, EDS and XRD. The mechanical properties of the brazed joints were measured by mechanical testing machine. The results showed that Ti element in the interlayer can reaction with the brazed composite, a mixture of Ti3 SiC2,Ti3Si and TiC composites finally formed the reaction layer between composite and interlayer. Ti alloy constantly dissolves and Cu diffuses into the Ti alloy, forming the diffusion - reaction layers between interlayer and Ti alloy. The performed joints have dense bonding layers reinforced by W. These composite brazing layers relaxed the thermal stress of the joint effectively. These characteristics were beneficial to the joint, of which the shear strength were remarkably highly than the optimal shear strengths of the joint brazed with pure AgCuTi.