Influence of nickel boride addition on sintering behaviour and mechanical properties of TiC-Ni based cermets

Abstract

TiC-Ni based cermets were prepared by vacuum sintering at 1200 degrees C, 1300 degrees C and 1400 degrees C. NiB (0, 10, 20 wt%) was added to improve sintering activity by creating a liquid phase and enhance the densification. The effects of NiB content on density, microstructure, hardness, elastic modulus, fracture toughness, and thermal expansion were studied. Density, micro hardness, elastic modulus, and fracture toughness, of the composite were increased by the addition of 10 wt% NiB. The 1400 degrees C sintered sample with 10 wt% NiB resulted in maximum densification with 97% of theoretical density. The 1400 degrees C sintered TiC-10Ni-10NiB showed better mechanical properties with elastic modulus of 470 GPa, hardness of 2759 HV and fracture toughness 8.98 MPa m(1/2), all better than that of TiC-20Ni sintered at same condition. (C) 2016 Elsevier B.V. All rights reserved.