X. H. Tan, Shanghai Baosteel Equipment Maintenance Co., Ltd, Shanghai, PRC, Shanghai, China; J. S. Sun, Tianjin Institute of Technology, Tianjin, PRC, Tianjin P.R., China
Abstract: WC-based cermet coatings were deposited by HVOF and an attempt was made to determine the laser remelting effects on the microstructures, hardness and dry sliding wear behavior of the coatings. The results indicated that the laser treatment employing the selected laser parameters allows the improvement of the quality of the HVOF sprayed WC-based cemet coatings and the elimination of porosity, and contributes to increased hardness and enforced metallurgical fusion between coating and substrate. Under this friction-wear test the micro-cracks on the worn surface of HVOF-sprayed WC cermet coatings and the adhesive transfer from friction pair of 45 steel to the coating surface occur. No micro-cracking of the worn surface of laser treated coatings has been found. Adhesive transfer from the friction pair to the laser-treated coating occurred.
Summary: Laser remelting can improve the quality of the HVOF sprayed WC-based cemet coatings. Using the selected laser remelting parameters, the laser treatment can produce a reasonable increment in the microhardness of the coating. The adherence also increases, probably due to process of diffusion of the iron contained in the base to the coating during laser remelting.Compared with as-sprayed WC-Co and WC-NiCr coatings, the laser-treated coatings possess higher dry sliding wear resistance.
