C_f/SiC复合材料与Ti合金的Ag-Cu-Ti-TiC复合钎焊

Brazing of C_f/SiC composite to Ti alloy using Ag-Cu-Ti-TiC composite filler materials

以Ag-Cu-Ti-TiC复合钎料为中间层,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和XRD分析接头的微观组织结构,利用剪切实验检测接头的力学性能。结果表明:钎焊时,借助液态钎料,复合钎料中的Ti与Cf/SiC复合材料反应,在Cf/SiC复合材料与连接层界面形成Ti-Si-C、Ti-Si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TiC颗粒强化的致密复合连接层,TiC的加入降低了接头的残余热应力,Cf/SiC/Ag-Cu-Ti-TiC/TC4接头的剪切强度明显高于Cf/SiC/Ag-Cu-Ti/TC4接头的。

Cf/SiC composite was joined with Ti alloy using Ag-Cu-Ti-TiC mixed powder as interlayer under condition of some suitable brazing parameters. The 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 show that Ti element in the interlayer can react with the brazed composite, a mixture of Ti-Si-C, Ti-Si and TiC composites finally form the reaction layer between the composite and interlayer. Ti alloy constantly dissolves and Cu diffuses into the Ti alloy, the diffusion reaction layers between the interlayer and Ti alloy forms. The performed joints have dense bonding layers reinforced by TiC. These composite brazing layers relax the thermal stress of the joint effectively. These characteristics are beneficial to the joint, of which the shear strength are remarkably higher than the optimal shear strength of the joint brazed with pure Ag-Cu-Ti.