Corrosion Behavior of WC-Co Coatings with VC Additions Applied by Thermal Sprayed HVOF

Abstract

The addition of nanostructured VC particles in coatings WC-Co improves the mechanical properties of cermet processed by the thermal spray technique HVOF. These coatings are used to protect components from wear, high temperature and corrosion. In the other hand these coatings are an alternative to replace chrome plating in aerospace industry. The objective was study the corrosion resistance of bimodal coatings WC-Co-VC applied by thermal spray HVOF with different concentration of VC on AISI 304. Bimodal mixtures were obtained from commercial micro and nanostructured powders. Then it was deposited on AISI 304 using a HVOF hybrid gun and robotized arm. The electrochemical characterization was performed by polarization resistance and potentiodynamic polarization curves. It was determined that the anodic polarization curves the coatings present a tendency to passivation; however, they were more pronounced in sodium hydroxide. Addition of nanostructured VC particles to the cermet WC-12Co didn't affect its corrosion resistance.