Effect of Rare Earth Y Addition on the Microstructure and Properties of Stellite6/WC Coating by Laser Cladding

Forty five steel is a commonly used metal material in the machinery manufacturing industry. To improve the hardness and wear resistance of 45 steel, a Stellite6/WC Co-based alloy composite coating with rare earth Y was prepared on a 45 steel substrate by laser cladding technology. The effects of different additions of rare earth Y on the morphology, phase composition, microstructure, microhardness, and wear resistance of Stellite6/WC composite coatings after laser cladding were studied, and the optimal addition of rare earth Y was determined. The results showed that the addition of 0.9 wt.% rare earth Y coating to a Stellite6/WC composite coating has the best comprehensive performance. The X-ray diffraction results showed that new phases such as Y₂O₃, Co₂Y, and Y₂Co₁₇ were formed after the addition of rare earth Y. Scanning electron microscopy showed that the coating bonding region was mainly composed of fine cellular crystals and columnar dendrites when the rare earth Y content was 0.9 wt.%, and that the upper region grains also became finer and the volume fraction of eutectics increased. Compared with the coating without the addition of rare earth Y, the maximum average microhardness was 629 HV_0.2, and increase of 18.1% and the wear mass loss was reduced by 60.9%.