Effect of Ni-coated WC reinforced particles on microstructure and mechanical properties of laser cladding Fe-Co duplex coating

Abstract

Fe-Co duplex coating has been deposited onto crystallizer copper plates surface by Nd: YAG laser cladding. To further improve the wear resistance of the duplex coating, the effects of various nickel-coated WC (Ni/WC) contents on the microstructural characterization and wear properties of different coatings have been investigated by using optical microscopy (OM), X-ray diffractometer (XRD), scanning electron microscope (SEM) and energy disperse spectroscope (EDS). The experimental results indicated that the microstructures of the Co-based layer were mainly composed of dendrite and eutectic structure, which were refined with increasing Ni/WC content. Compared with the Co-based layer without Ni/WC, the addition of Ni/WC facilitated the formation of new phase Co3W9C4 and WC. Moreover, the decomposition of WC particles on the Co-based layer enhanced the effect of solid solution strengthening, resulting in an improvement of the microhardness and wear resistance of the working layer. Based on the obtained results, the incorporation of Ni/WC was an attainable way to improve the tribological properties of Co-based alloy coatings.