Modification of corrosion and tribological properties of 316L stainless steel by cathodic plasma electrolytic deposition of zirconia

Purpose – This paper aims to study the deposition of ZrO2 on 316L stainless steel surface using cathodic plasma electrolytic deposition (CPED) technique in potassium hexafluorozirconate (K2ZrF6) electrolyte solution to promote its corrosion and tribological properties. Design/methodology/approach – Plasma electrolytic oxidizing (PEO) technique is commonly used to form zirconium dioxide (ZrO2) on various substrates. But, in this paper, cathodic type of this technique (CPED) was used. Findings – Composition of the surface layer was analyzed by X-ray diffraction (XRD) and the formation of ZrO2 on the substrate was confirmed. Scanning electron microscope (SEM) was used to observe the unique morphology of the surface layer. The corrosion resistance of the coated surface was investigated by electrochemical methods involving cyclic voltammetery in Ringer’s solution. The treated sample showed a better pitting resistance. Pin-on-disk wear tests revealed that the friction coefficient of the coated sample is lower than that of the substrate. Also, it was shown that hardness and roughness of the coated sample increased after plasma electrolytic treatment. Originality/value – This paper considers the CPED of ZrO2 coating on 316L stainless steel. Some recent research works with ZrO2 coating have been prepared by PEO. There is limited or no record on the study of ZrO2 coatings by CPED process. In this study, the effort has been made to prepare a zirconia (ZrO2) coating on the stainless steel substrate through cathodic plasma electrolytic process under 200 V. Due to the excellent wear resistance, ZrO2 may be used as a high resistant and protective coating on stainless steels, which are widely used in industries and biomedical applications.