XPS and EDS Analysis of VC Coatings Prepared by TD Process

VC (vanadium carbide) coating was prepared on the substrate surface of Cr12MoV cold worked die steel by TD (thermal diffusion) process using anhydrous borate, FeV50, FeSi45 as main materials. The structures and the chemical element distributions of the coating were characterized with SEM (scanning electron microscope), XRD (X-ray diffraction), XPS (X-ray photoelectron spectroscopy) and EDS (energy dispersive spectrometer), respectively. The chemical element distributions of VC coating surface and interface were analyzed with plane scan of EDS, and the mechanism of interfacial metallurgical bonding was discussed. The results show that the VC coating is a compound, consisting of C and V elements, and the concentration of V atom is twice as large as that of C atom. The VC coating is single VC phase, where the electron binding energy of V element is located at 512.8 eV, and that of C element is located at 282.2 eV. The diffusion between V, C and Fe elements occur at the coating interface and a layer of interface diffusion is formed, and the interface of VC coating-substrate is combined with the metallurgical bonding.