Laser surface cladding of stellite and stellite-SiC composite deposits for enhanced hardness and wear

Hard and wear-resistant alloy and composite clad layers have been produced on En 3b mild steel substrate using a 2 kW continuous wave CO2 laser. Stellite alloy 6 and a mixture of Stellite alloy 6 and SiC in various proportions were blown into the melt pool by means of a pneumatic powder delivery system. A comparative study of structure, chemical composition, wear and hardness has been made to evaluate the effect of incorporated SiC particles. The extent of dilution by iron from the substrate was lower in Stellite alloy clads than in its composite with SiC particles, but the latter was found to have a substantially higher hardness and wear resistance than the former. The microhardness was found to be increased from 540–580 Hv for the Stellite alloy 6 clad to about 1390 Hv for the matrix region of the composite by the inclusion of about 19 wt.% SiC in the cladding mixture.