We 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.Keywords: Coatings, thermo reactive, niobium-vanadium carbide, spectroscopy, impedance. RESUMEN En este trabajo se depositaron recubrimientos de carburo de niobio-vanadio sobre aceros para herramientas AISI H13 utilizando la técnica de depósito por difusión termorreactiva (TRD). Los carburos se obtuvieron utilizando baños de sales compuestas de bórax fundido, ferroniobio, vanadio y aluminio, calentando la mezcla a 1020 °C durante 4 horas. Los recubrimientos fueron caracterizados morfológicamente mediante microscopia electrónica de barrido (SEM), la composición química de la superficie se determinó mediante espectroscopia de fotoelectrones de rayos X (XPS) y la espectroscopia de rayos X de energía dispersiva (EDX); la estructura cristalina se analizó utilizando difracción de rayos X (XRD), las propiedades mecánicas de los recubrimientos fueron evaluados utilizando nanoindentación. Las propiedades tribológicas de los recubrimientos obtenidos fueron determinadas usando un tribómetro Pin on Disk CETR-UMC-2 y el comportamiento electroquímico se estudió por medio de curvas de polarización potenciodinámica y espectroscopia de impedancia electroquímica (EIS). Los resultados mostraron que la dureza del acero revestido aumentó cuatro veces respecto del acero no recubierto, y la prueba electroquímica estableció que la corriente de corrosión es inferior en un orden de magnitud para el acero recubierto.Palabras clave: Recubrimientos, termorreactiva, carburo de niobio-vanadio, espectroscopia, impedancia.

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The functional properties of the transition-metal nitride coatings can be modified by adding noble metals such as silver. The incorporation of these elements has been demonstrated to be a good strategy for improving the electrical, optical, and mechanical responses of transition-metal nitride coatings. In this investigation, we report the production of Ag-ZrSiN coatings with varying silver atomic contents, deposited using pulsed-DC reactive magnetron sputtering. The effect of the incorporation of silver on the microstructure, the morphology, and the optical and electrical properties was investigated. The results revealed a nanocomposite structure of Ag-ZrSiN with nc-Ag/nc-ZrN embedded in an amorphous SiNx phase. The electrical resistivity decreased upon the incorporation of Ag from 77.99 Ω·cm to 0.71 Ω·cm for 0.0 and 12.0 at.% of Ag, respectively. A similar decreasing trend was observed in the transmittance spectra of the coatings as the silver content increased. For the Ag-ZrSiN coating, the transmittance values decreased within the wavelength range of 2500–630 nm and then remained constant down to 300 nm, at about 13.7%. Upon further increase of the silver concentration up to 12 at.%, the transmittance values continued to decrease between 2500 and 630 nm, reaching approximately zero at 630 nm, indicating that the coating becomes opaque within that spectral range.

Many components in the shipbuilding industry are made of copper-based alloys. These pieces tend to break due to corrosion generated by a marine environment; such components can be salvaged through surface engineering, through deposition of suitable coatings. This paper studied the influence of three surface preparation methods involving phosphor bronze substrates concerning the corrosion resistance of commercial coatings having Al-Cu +11% Fe chemical composition. The surface was prepared using three methods: sand blasting, shot blasting and metal polishing with an abrasive disk (with and without a base layer). The deposited coatings were microstructurally characterised by x-ray diffraction (XRD), optical microscopy and scanning electron microscopy (SEM). Corrosion resistance was evaluated by electrochemical test electrochemical impedance spectroscopy (EIS). Surfaces prepared by sandblasting showed the best resistance to corrosion, so these systems could be a viable alternative for salvaging certain parts in the marine industry. The corrosion mechanisms for the coatings produced are discussed in this research.