Microstructure and shear strength of diffusion brazed Al₂O₃-TiC/Q235 joint

An Al₂O₃-TiC/Q235 joint, Al₂O₃-TiC ceramic composite with steel Q235, was obtained by diffusion brazing in vacuum, using a combination of Ti and Cu as multi-interlayer.The interfacial strength was measured by shear testing and the result was explained by the fracture morphology.Microstructure of the Al₂O₃-TiC/Q235 joint was investigated by scanning electron microscope (SEM), energy-dispersion spectroscopy (EDS)and X-ray diffraction (XRD).The results indicate that the Al₂O₃-TiC/Q235 joint with a shear strength of 122 MPa can be obtained by controlling heating temperature at 1 110℃, multi-interlayer Ti/Cu/Ti is fused fully and diffused reaction to produce an obvious interfacial transition zone with a thickness of about 80 μm, and there are Ti₃AlC₂, Fe₂Ti, Cu and TiC in the transition zone.