Microstructure and Mechanical Performances of C/C Composite and TC4 Alloy Brazed Joints

C/C composite and TC4 alloy were successfully brazed using 70Ag28Cu2Ti (wt. %) as filler metal at brazing temperature 820 º°C~920 °C for soaking time 5 min ~30 min. The effects of brazing parameters on the microstructures and phase composition and the fracture modes of the brazed joints were investigated by SEM and XRD. The mechanical performances of the brazed joints were measured by a universal mechanical testing machine. The results show that the maximum shear strength of the brazed joint is 28 MPa at brazing temperature 860°C and soaking time 10min. Fracture surface analysis of the brazed joints indicates that the position of the fracture surface is related to the orientation of carbon fiber. The brazed joints are fractured in the C/C composite when the carbon fiber is parallel to the joined surface, and the brazed joints are fractured at the C/C composite / 70Ag28Cu2Ti interface when the carbon fiber is vertical to the joined surface.