Wear resistance of WCp/Duplex Stainless Steel metal matrix composite layers prepared by laser melt injection

Laser Melt Injection (LMI) was used to prepare metal matrix composite layers with a thickness of about 0.7 mm and approximately 10% volume fraction of WC particles in three kinds of Cast Duplex Stainless Steels (CDSSs). WC particles were injected into the molten surface layer using Nd:YAG high power laser beam. As a result the microstructure characterized by hard ceramic particles distributed in a metal matrix with the strong bonding to substrate is formed in the surface layer of the treated metal.Dry sliding wear properties of these metal matrix composites layers were measured and compared with the wear properties of the substrate and with surfaces simply remelted by the laser beam. The observed wear mechanisms are summarized and related to detailed microstructural observations. The layers have been found to show excellent interfacial bonding, coupled with substantially improved tribological properties expressed through the wear resistance increase of 8 times. The amount of WC particles was sufficient to reinforce the matrix and the particles have shown a good bonding to the matrix to support the contact stress in the layer.