Microstructure and properties of hard and wear resistant MMC coatings deposited by laser cladding

Laser coating (laser cladding) is a useful method to produce metal matrix composite (MMC) coatings. The selection of the metallic matrix can be done on the base of the intended application and environment, whereas the additional wear resistance improvement is provided by mixing various carbides with the metallic matrix. In the present work, various types of MMC coatings were prepared by laser coating methods. The coatings consisted of vanadium, tungsten, titanium and chromium carbide hard phases mixed with metallic tool steel M2, Stellite 21, NiCrBSi-alloy and Inconel 625. Different levels of carbide contents were used. The abrasion resistance of the MMC coatings has been tested using a rubber-wheel abrasion apparatus. The wear surfaces were examined and the microstructures of MMC coatings were analysed in order to determine microstructures and carbide dissolution. The best abrasion results were achieved by the correct choice of carbide for each matrix material.