Interfacial microstructure and strength of diffusion brazed joint between Al2O3-TiC and 9Cr1MoV steel

Abstract

Joining of composite, Al2O3-TiC, with heat-resistant 9Cr1MoV steel, was carried out by diffusion brazing technology, using a combination of Ti, Cu and Ti as multi-interlayer. The interfacial strength was measured by shear testing and the result was explained by the fracture morphology. Microstructural characterization of the Al2O3-TiC/9Cr1MoV joint was investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM) with energy-dispersion spectroscopy (EDS). The results indicate that a Al2O3-TiC/9Cr1MoV joint with a shear strength of 122 MPa can be obtained by controlling heating temperature at 1130°C for 60 min with a pressure of 12 MPa. Multi-interlayer Ti/Cu/Ti was fused fully and diffusion occurred to produce interfacial layer between Al2O3-TiC and 9Cr1MoV steel. The total thickness of the interfacial layer is about 100 μm and Ti3AlC2, TiC, Cu and Fe2Ti are found to occur in the interface layer.