Electrochemical Properties of TiWN/TiWC Multilayer Coatings Deposited by RF-Magnetron Sputtering on AISI 1060

Abstract

Nitride and carbide ternary coatings improve the wear and corrosion resistance of carbon steel substrates. In this work, Ti-W-N and Ti-W-C coatings were deposited on AISI 1060 steel substrates using reactive radio frequency (RF) magnetron sputtering. The coatings were designed as monolayers, bilayers, and multilayers of 40 periods. The coatings were obtained with simultaneous sputtering of Ti and W targets. The microstructure, composition, and electrochemical properties were investigated by techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization. XRD results shower a mix of binary TiN and W2N structures in the Ti-W-N layer, a ternary phase in Ti-W-C layers, in addition of a quaternary phase of Ti-W-CN in the multilayers. The analysis of the XPS demonstrated that the atomic concentration of Ti was more significant than W in the Ti-W-N and Ti-W-C layers. The lowest corrosion rate (0.19 mm/year−1) and highest impedance (~10 kΩ·cm2) out of all coatings were found in n = 40 bilayers. In the simulation of equivalent electrical circuits, it was found that the Ti-W-N coating presented three processes of impedance (Pore resistance + Coating + Inductance). However, the multilayer (n = 40) system presented a major dielectric constant through the electrolyte adsorption; therefore, this caused an increase in the capacitance of the coating.

Relationship analysis of surface roughness measurements on coatings using AFM and fractal dimension by mesoscopic model methods

“…This method can reduce costs using special equipment, essential conditions, and it time-consuming to measure [13], an alternative for researchers with limited sources, such as Latin-American countries. Our proposal study presents coatings based on carbide tungsten-titanium/nitride tungsten-titanium from ternary (Ti-W-C) to quaternary (Ti-W-C-N) compound systems deposited on the substrate according to American Iron and Steel Institute (AISI) 1060 carbon steel in the bilayer (named as n = 1) and forty-bilayers (named as n = 40) published by [14]. Depending on the characterization resource method, the increase in period deposition affects microstructure surface, promoting significative error measurements on roughness performance.…”