Effects of Cr on Microstructure and Hardness of HVOF-Sprayed WC-Co Coating
In the areas of remanufacturing and working conditions with requirements of wear and corrosion resistance, the WC-Co thermal spray coating has a wide applications. WC-10Co-4Cr is an excellent, has great application potential as a coating composition. In this research, the two kinds of coatings, WC-12Co and WC-10Co-4Cr, were sprayed by high velocity oxygen-flame(HVOF). The phase composition is studied by X-ray diffraction(XRD). The porosity is investigated by lase confocal scanning microscope(LCSM), and the micro-hardness is measured. The results show that, The porosity of two coatings don't differ, this maybe has relation with the parameters in the spraying process.The micro-hardness of WC-10Co-4Cr coating is higher than that of WC-12Co coating. Compared with the phase composition of WC-12Co coating, there are new phase composition Cr7C3, Cr23C6 and Cr2WO6 in the WC-10Co-4Cr coating. And the content of W2C and η phase are reduced in WC-10Co-4Cr coating. Cr had no effect on the lattice transformation of cobalt.
L. J. Wang et al., "Effects of Cr on Microstructure and Hardness of HVOF-Sprayed WC-Co Coating", Advanced Materials Research, Vols. 317-319, pp. 301-306, 2011