Microstructure and wear resistance of Stellite-6/WC MMC coatings produced by laser cladding using Yb:YAG disk laser

The paper focuses on the study results of Stellite-6/WC metal matrix composite coatings (MMC coatings) produced by laser cladding technology using a 1 kW continuous wave Yb: YAG disk laser with powder feeding system. Specimens were preparation using CNC machining center equipped with a laser nozzle. Powder mixtures containing 60% tungsten carbides particles and 40% commercial Stellite-6 powder were used. In this study, three different values of laser beam power (400 W, 550 W and 700 W) and three different powder feed rate (5.12 g/min, 10.24 g/min and 15.36 g/min) were used. For all specimens, the same scanning speed of laser beam were applied. Changes in roughness, microstructure as well as wear resistance were investigated. It was found that increasing laser beam power caused a decrease in wear resistance of coating. Furthermore in described process appeared the best value of the powder feed rate which potentially resulting in better wear resistance. Exceeding this value influence on more intensive wear of coating. Special attention was given to the wear mechanism of MMC coatings.