Nitriding of tungsten carbide alloy powders for wear-resistant coating

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This proposal aims to develop a nitriding treatment for reducing the miscibility of tungsten carbide (WC) powders within liquid metal matrices. It addresses a problem of major interest for Recentis Advanced Materials, a company specialized in the fabrication of highly resistant coatings, who has developed a new family of tungsten carbide alloys ((W,M)CX M=Ti, V, Nb, Zr) targeting improved mechanical properties and chemical stability, for applications in metallurgy, aerospace, automotive and tool industries. The proposed methodology is based on the testing of a large variety of nitriding processes and additional gas thermal treatments, followed by advanced measurements for process characterization and optimization. Gas nitriding is a surface hardening process, where nitrogen is added to the surface of materials using dissociated ammonia as the source. Both the composition and the morphology of all treated samples (carbide powders and substrates) will be subsequently analyzed by Raman spectroscopy, x-ray diffraction (XRD), X-ray Photoelectron Microscopy (XPS), Atomic Force Microscopy (AFM) and scanning electron microscopy (SEM), in order to determine the efficiency of each gas treatment and guide our industrial partner towards the best process. Our research will more specifically focus on the core-shell structure of the processed WC micrograins whose improved thermo-mechanical properties can reduce their dissolution during the welding process and enhance the wear resistance of carbide-containing metal matrix composites. All implemented treatments will be achieved in close collaboration between Recentis and INRS and within the feasibility parameters of industrial partners based in Canada, for immediate technology transfer.