Influence of Deposition Parameters on Structural and Electrochemical Properties of Ti/Ti2N Films Deposited by RF-Magnetron Sputtering

Abstract

The titanium nitride (Ti2N) films have good mechanical properties, such as high hardness and chemical stability, giving Ti2N good resistance to wear and corrosion. The properties of films deposited by PVD techniques are determined by their structure, microstructure, composition, and morphology that depend on the deposition parameters, such as substrate temperature, vacuum pressure, and the distance between the target and the substrate. The influence of these parameters has been studied individually. This work studied the structure, morphology, composition, and electrochemical behavior of Ti/Ti2N films deposited by RF-magnetron sputtering on carbon steel, such as a function of the power of the RF source, substrate temperature, and the target to substrate distance and the Ar/N2 ratio. The film structure was analyzed by X-ray diffraction (XRD), the morphology of cross-section by SEM, the semi-quantitative composition by EDS, and the electrochemical properties was studied by open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques. The films showed two phases of Ti and Ti2N. The SEM-EDS exhibited a morphology according to the Stranski–Krastanov or layer-plus-island growth model. The substrate temperature of 450 °C strongly influences the electrochemical properties.