Microstructure and mechanical properties of C/C composite/TC4 joint using AgCuTi filler metal

C/C composites and a titanium alloy were joined using AgCuTi filler metal at 860–1000 °C for 3–30 min. The effects of brazing parameters on the microstructures of the brazed joint were investigated by SEM, EDS and XRD. The mechanical properties of the brazed joints were measured by an Inston-1186 mechanical testing machine. The results show that the brazed joint mainly consists of TiC, TiCu, Ti3Cu4 and Ti2Cu reaction products. TiC + C/TiCu reaction layers are formed near C/C composite while Ti3Cu4/TiCu/Ti2Cu/Ti2Cu + Ti (s.s) reaction layers are formed near TC4. The thickness of reaction layers of the brazed joint increases while the amount of TiCu + Ti3Cu4 in the middle of the filler metal decreases with the increased brazing temperature or holding time. The maximum shear strength of the brazed joints is 25 MPa at brazing temperature T = 910 °C and holding time t = 10 min.