Microstructure and wear resistance of c-BN/Ni-Cr-Ti composites prepared by spark plasma sintering

c-BN/Ni-Cr-Ti composites were fabricated by spark plasma sintering. The microstructure and the interfacial structure were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction analysis. The results show that the Ni-Cr-Ti alloy exhibits a good wettability to cover the c-BN particles. The interfacial bonding is strong and an interfacial reaction layer was found at the interface. The microscopic analysis revealed that Ti is the active element in the Ni-Cr-Ti alloy which is enriched in the c-BN particles and interacts with N and B, resulting in the formation of TiB2, TiB and TiN and promoting the chemical metallurgical bonding between the Ni-Cr-Ti alloy and c-BN. The non-smooth surface formed by the relative protrusion of the c-BN particles with their high hardness can resist the wear of the friction pairs during the wear experiments. The failure mode of the c-BN/Ni-Cr-Ti composites is fatigue shedding of the reinforcing hard phases of the c-BN particles as well as the micro-cutting and transfer of the Ni-based alloy surface. (C) 2015 Elsevier Ltd. All rights reserved.