Electrochemical and wear behavior of niobium-vanadium carbide coatings produced on AISI H13 tool steel through thermo-reactive deposition/diffusion

Abstract

espanolEn este trabajo se depositaron recubrimientos de carburo de niobio-vanadio sobre aceros para herramientas AISIH13 utilizando la tecnica de deposito por difusion termorreactiva (TRD). Los carburos se obtuvieron utilizando banos de sales compuestas de borax fundido, ferroniobio, vanadio y aluminio, calentando la mezcla a 1020 °C durante 4 horas. Los recubrimientos fueron caracterizados morfologicamente mediante microscopia electronica de barrido (SEM), la composicion quimica de la superficie se determino mediante espectroscopia de fotoelectrones de rayos X (XPS) y la espectroscopia de rayos X de energia dispersiva (EDX); la estructura cristalina se analizo utilizando difraccion de rayos X (XRD), las propiedades mecanicas de los recubrimientos fueron evaluados utilizando nanoindentacion. Las propiedades tribologicas de los recubrimientos obtenidos fueron determinadas usando un tribometro Pin on Disk CETR-UMC-2 y el comportamiento electroquimico se estudio por medio de curvas de polarizacion potenciodinamica y espectroscopia de impedancia electroquimica (EIS). Los resultados mostraron que la dureza del acero revestido aumento cuatro veces respecto del acero no recubierto, y la prueba electroquimica establecio que la corriente de corrosion es inferior en un orden de magnitud para el acero recubierto. EnglishWe deposited of niobium-vanadium carbide coatings on tool steel AISI H13 using the thermo-reactive substrates deposition/diffusion (TRD) technique. The carbides were obtained using salt baths composed of molten borax, ferroniobium, vanadium and aluminum, by heating this mixture at 1020° C for 4 hours. The coatings were characterized morphologically via electron microscopy scanning (SEM), the chemical surface composition was determined through X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray spectroscopy (EDX); the crystal structure was analyzed using x-ray diffraction (XRD), the mechanical properties of the coatings were evaluated using nano-indentation, The tribological properties of the coatings obtained were determined using a Pin-on-disk tribometer and the electrochemical behavior was studied through potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that the hardness of the coated steel increased four times with respect to uncoated steel, and the electrochemical test established that the corrosion current is lower by one order of magnitude for coated steel.