Microstructure and mechanical properties of the GH783/2.5D C/SiC joints brazed with Cu–Ti + Mo composite filler

Using Cu–Ti + Mo composite filler, 2.5 dimension carbon-fiber-reinforced SiC (2.5D C/SiC) composites were brazed to GH783 under vacuum condition. Effect of Mo content on the microstructure and mechanical properties of the joints were investigated. The results showed that the joints were composed of four regions: a reaction layer, a stress relief layer, a residual Cu layer and a diffusion layer. The maximum flexural strength of the joints with 10 vol.% Mo particles reached 198 MPa, which was 133.8% higher than the average strength of the joints without Mo particles, and the flexural strength decreased when Mo content increased more than 10 vol.%. The additional Mo released the joint residual stress, inhibited Ti and C/SiC excessive reaction, and thus effectively improved the strength of joints.