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

The wear behaviour of sintered high-speed steel-type particulate compo sites depends significantly on microstructural parameters, such as tho se of the metallic matrix and primary carbides, but also on some addit ional parameters related to the powder metallurgy processing. Pin-on-d isc test results, coupled with scanning electron microscopy (SEM) obse rvation of the wear tracks and microstructure image analysis, indicate d the prominent role of the added ceramic particles. More precisely, t he 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 role s of the residual porosity and of the presence of copper as a solid lu bricant are pronounced in this investigation.