Influential effects of laser remelting on plasma-sprayed Ni60A/Ni-WC coating on high Al-Zn sinking roller

Abstract

In order to improve the performance of the plasma-sprayed Ni60A/Ni-WC composite coatings on the surface of high AlZn sinking roller, the as-sprayed Ni60A/Ni-WC coatings were treated using laser remelting technology, and the influential effects of laser remelting on the microstructure and performance of the Ni60A/Ni-WC coating was studied. The surface morphologies, microstructure, and microhardness of the Ni60A/Ni-WC coatings were analyzed using scanning electron microscopy (SEM) and microhardness tester. The high-temperature friction and wear characteristics of the Ni60A/Ni-WC coatings were also investigated. The results show that laser remelting treatment eliminates the defects such as lamellar structure and pores of the as-sprayed Ni60A/Ni-WC coatings, and the coatings density is improved. In addition, under the action of the high energy density laser, WC particles partially melt and precipitate dendritic structures around WC particles. The microhardness of Ni60A/Ni-WC coatings after laser remelting treatment are significantly improved, and their wear resistance are also significantly higher than that of the as-sprayed coatings.