Shear strength and fracture characteristics of the Al2O3-TiC/Q235 vacuum diffusion bonded joint

Diffusion bonding of composite ceramics Al2O3-TiC to low carbon steel Q235 has been carried out by using Ti/Cu/Ti as multi-interlayer. The microstructure and fracture morphology of Al2O3-TiC/Q235 diffusion bonded joint were studied via scanning electron microscopy and electron probe microanalysis. The results indicate that an interfacial transition zone was formed between Al2O3-TiC and Q235. The Al2O3-TiC/Q235 diffusion bonded joints were produced with the shear strength of 111 MPa. As the Al2O3-TiC/Q235 joint was subjected to a shear force, only elastic deformation occurred, since the load-displacement curve is a typical brittle fracture curve of the ceramics. It shows that the fracture occurred inside the Al2O3-TiC ceramics, and the strength of the interfacial transition zone is higher than that of the Al2O3-TiC ceramics. The morphology of the fracture surfaces in the Al2O3-TiC ceramics possesses typical features with a mirror region, a mist region, and a hackle region.