SLIDING-WEAR BEHAVIOR OF CERAMIC PARTICLE-REINFORCED HIGH-SPEED STEEL OBTAINED BY POWDER-METALLURGY

The wear behaviour of sintered high-speed steel-type particulate composites depends significantly on microstructural parameters, such as those of the metallic matrix and primary carbides, but also on some additional parameters related to the powder metallurgy processing. Pin-on-disc test results, coupled with scanning electron microscopy (SEM) observation of the wear tracks and microstructure image analysis, indicated the prominent role of the added ceramic particles. More precisely, the size, the mechanical resistance and the cohesion with the metallic matrix of TiC, uncoated Al2O3, and TiN-coated Al2O3 particles, largely determine the wear behaviour of such materials. In addition, the roles of the residual porosity and of the presence of copper as a solid lubricant are pronounced in this investigation.