MICROSTRUCTURE AND MECHANICAL-PROPERTIES OF SOME METAL-MATRIX COMPOSITES COATINGS BY LASER CLADDING

During the last decade, many studies have been devoted to metal matrix composites (MMC), consisting of hard ceramic materials embedded in a metallic substrate. The metallic matrix provides the necessary ductili ty, whilst the hard phase provides the high hardness, the high Young m odulus and the good wear resistance. Laser cladding can be used to ela borate such MMC; by adjusting laser power and interaction time, it is possible to melt the metallic elements without affecting the hard phas es (oxides, carbides .). The present work deals with the elaboration a nd the characterization of MMC coatings on different substrates (coppe r- or iron-base materials). Metallic matrix is constitued by a nickel base material and tungsten carbides are used as hard particles.