Organization of clad layer using mixed powder of stellite 6 and VC

A laser robot cladding system was set by using pulsed 300 W Nd: YAG laser facility, 6-axis robot, a optical fiber of 5 m in length, powder feeding system and special nozzle for powder supply. Stellite 6 alloy and VC mixed powder were cladded on mild steel (SM400B) plate. Shape of clad layer, microstructure and performance of clad layer were investigated by changing the weight fraction of VC in the range of 0 to 100%. The experimental results demonstrated that as the weight fraction of VC in the powder mixture increases in the range of 0 to 80%, the amount of primary solidified VC phase and penetration depth increased. Depending on the weight fraction of VC in the powder, the resultant microstructures can be divided into two types - hypoeutectic structure containing primary Co-richγ phase with eutectic structure and hypereutectic structure containing primary VC, complex carbides and eutectic structure.