Preparation and characterization of high-performance in-situ synthesized WC reinforced nickel-based coatings

Abstract

The WC prepared by in-situ synthesis usually has the deficiency of coarse grains and low synthetic content due to its low nucleation drive. In this work, different contents of WCs were added as nucleation sites to enhance the synthesis reaction between carbon and tungsten by reducing the nucleation energy. The results showed that the composite coatings were dense, crack-free, and mainly composed of WC and Fe0.64Ni0.36 phases. Due to a significant increase in the nucleation rate, the content of WC was increased from 38.08% to 53.15% and the WC grains were also significantly refined. The composite coating showed the lowest wear rate of 1.07 × 10−6 mm3 N−1 m−1 when the pre-added WC content was 15 wt%, which was ascribed to the high content of synthetic WC with high microhardness around 2200 HV0.1 and the fine grain strengthening of the large number of about 1 μm WCs.

Keywords

• Laser cladding
• In-situ synthesis
• WC
• Nucleation site
• Tribological properties