Microstructures and Properties of NiCrBSi/WC Biomimetic Coatings Prepared by Plasma Spray Welding

The NiCrBSi/WC biomimetic coatings were prepared on the low carbon steel substrate by plasma spray welding with mixed powders (WC-Co12+NiCrBSi) based on the bionic principles, and the coating characteristics were investigated. The results indicate that the coatings have a full metallurgical bond in coating/substrate interface, and consist mainly of γ-Ni, WC, Cr23C6, Cr7C3, Ni3Si, Cr5B3, and FeNi3 phases. The powder composition influences the microstructures and properties of the coatings. The WC content and the hardness of coatings increase with the mass fraction of WC-Co12 powder. The biomimetic coatings have much higher wear resistance compared with the low carbon steel, which is attributed to the combination of hard WC and chromium carbide particles (bionic units) and soft γ-Ni matrix in the coatings. It is favorable to prepare the biomimetic coating by plasma spray welding with the mixed powders (20wt%WC-Co12+80wt%NiCrBSi) for improving the wear resistance of the coating.