Laser surface treatment of a low carbon steel by cladding with tungsten carbide composite powders

Cracking is a serious problem in the laser surface treatment using carbide injection, say tungsten carbide or titanium carbide. One way to solve this problem is the laser cladding with a composite powder mixture consisting of carbide particles and a ductile metal alloy as a binder. In the present work a powder composite of 60 wt% WC/Co and 40 wt% NiCrBSi is cladded onto a low carbon steel. A detailed parameter optimization is discribed to get a reproducible composite coating free of cracks and almost free of iron dissolution. Abrasive wear tests show that the wear rates of this surface coating are comparable with that of sintered WC/Co hard metal.