High temperature wear behavior of WC particles reinforced Ni-based plasma-sprayed coating by laser remelting

To improve the properties of tungsten carbide(WC) particles reinforced Ni-based coating prepared by plasma spraying, laser remelting experiment was carried out and the effects of laser remelting on microstructure and properties on coating were studied.The surface morphology, microstructure, phase and microhardness of coatings were investigated by using scanning electron microscopy(SEM), X-ray diffractometry and microhardness measurement.Meanwhile, the high temperature fiction and wear behavior for both coatings were comparatively studied.The results showed that the defects of as-sprayed coating like lamellar stacking microstructure and pores were eliminated by laser remelting, and the remelted coating possessed a denser microstructure.In addition, WC particles partly dissociated at the edge, and the dendrite grew from the surface of the partially melted WC particles under high energy density laser.The laser-remelted sample had higher hardness, better wear resistance than the as-sprayed coating.