Wear behaviour and electrical conductivity of β-Sialon-ZrN composites fabricated by reaction bonding and gas pressure sintering process

beta-Sialon-ZrN composites with different levels of substitution and ZrN content have been formed by a process of reaction bonding and post gas pressure sintering, and the wear properties and electrically conductive properties have been investigated. The results showed that an appropriate higher sintering temperature was beneficial for increasing wear resistance, and the composites with beta-Sialon (Z = 1) had better wear properties than those with beta-Sialon (Z = 4). The incorporation of the ZrN particles was observed to have an effect on the wear properties of the composites. The best wear properties was observed for the composites sintered at 1700 degrees C with lowest wear rate of 2.4 x 10(-5) mm(3)N(-1)m(-1) for beta-Sialon (Z = 1)-20 wt% ZrN and 5.0 x 10(-4) mm(3)N(-1)m(-1) for beta-Sialon (Z = 4)-30 wt% ZrN, respectively. The wear resistance was influenced by numerous factors, including phase composition, microstructure, hardness and fracture toughness, and the material was mainly removed by delamination, micro-fracture and micro-cracks. At a given ZrN content, a continuous electrically conductive network was formed and had an effect on the electrical resistivity of the composites, where the electrical resistivity decreased from around 10(12) Omega.m for monolithic beta-Sialon to around 10 Omega.m for 23 vol% ZrN.