Abrasive Wear Properties of Metal Matrix Composites Produced by Hot Isostatic Pressing

Steel matrix composites are an attractive choice for paper, pulp and mineral crushing industries because of their wear resistant properties. In this paper the abrasive wear properties of the tool steel matrix composites are studied. The rubber wheel abrasion tests were carried out using six different composites. The tool steel Ralloy WR6 was used as matrix material in all composites. Typically there is about 20 vol% VC in the matrix before the addition of the particle reinforcements. Reinforcements were either cemented carbides (WC-Co), cast tungsten carbides (WC) or niobium carbides (NbC). All the composites were so-called double dispersion composites having two distinctive reinforcement types. Although the wear resistance of the composite materials has been found to increase with reinforcement additions in rock crushing environment with multimode wear conditions, the pure abrasion resistance of the composites, having up to 30% additional reinforcements, was found inferior to the matrix tool steel. Based on the observations it is suggested that in order to improve the abrasive wear resistance of the tool steels by adding hard particles, the matrix-particle interface should be strong enough to prevent the detachment of particles and the amount of particles should be high enough to compensate the accelerated wear of the matrix because of hard particle wear debris.