Research on brazing joints of C_f/SiC and TC4 using AgCuTi-Al filler materials

Cf/SiC composite and TC4 were successfully joined with the AgCuTi-Al mixed powders by appropriate brazing parameters under the vacuum condition.Microstructures of the joints were investigated by SEM,EDS and XRD.The mechanical properties were measured by mechanical testing machine as well.The results showed that Ti element in the brazing filler can react with the carbon fiber and the matrix SiC in the Cf/SiC composite,a mixture of TiC,Ti3SiC2 and Ti5Si3 finally formed in the reaction layer between the composite and the interlayer.The Ti element in the brazing filler and the Cu in the TC4 generated the mutual diffusion,which form the diffusion-reaction layers between interlayer and TC4.The addition of proper Al power of the Ag-Cu-Ti in-situ synthesized Ti3Al,finally the performed joints have dense bonding layers reinforced by the Ti3Al intermetallic compound,which relax the thermal stress of the joints effectively.The shear strength of the joint brazed with the AgCuTi-Al filler was remarkably higher than that of pure Ag-Cu-Ti filler.