Electrochemical study of nanocrystalline plasma electrolytic carbonitriding of CP-Ti

Abstract

Purpose - The aim of this paper is to obtain optimal corrosion resistance of certain differently treated samples by investigation of their electrochemical properties. Design/methodology/approach-Nanocrystalline plasma electrolytic carbonitriding (PEC/N) treatments were applied on the surface of commercially pure titanium in a glycerol bath with different additives. The carbonitriding process was performed in a glycerol bath with different additives such as carbamide, natrium nitrate and triethanolamine. The effects of electrolyte composition on chemical composition and corrosion resistance of the PEC/N films were examined by means of X-ray diffraction, scanning electron microscopy, potentiodynamic polarization and electrochemical impedance spectroscopy in a Ringer solution. Findings - The results showed that the PEC/N films obtained in solutions with triethanolamine (T-film) had better corrosion resistance. All coated samples had a better electrochemical behaviour compared with the untreated substrate. Different nano-structures and morphologies were obtained by different additives in electrolyte. Practical implications - The results obtained in this research into nanocrystalline PEC/N can be used wherever good corrosion and wear resistance with the highest efficiency is required. Originality/value - The speed of treatment by this technique makes this method very suitable for the industrial surface treatment of different components.