Fabrication and characterization of C₃N₄ coating by electrochemical deposition on stainless steel

In this study, C₃N₄ coating was successfully fabricated on AISI 304 stainless steel by electrochemical deposition method using N-N dimethylformamide (DMF) and KCl as the electrolyte. The influences of DMF concentration on the microstructure, hardness, and wear resistance of the coatings were investigated by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Vickers hardness tester, and pin-on-disk wear tester. The results indicate that a continue C₃N₄ coating layer can be formed on the steel surface. Compared to the untreated sample, the surface hardness and wear resistance of the stainless steel can be improved apparently after depositing of C₃N₄ coating. The hardness and wear resistance of the coatings increase firstly and then decrease with increase of DMF concentration. The coatings fabricated with 50 % DMF possess the highest hardness of 1329 HV_0.05 and the lowest friction coefficient of 0.35 at 5 N. The main wear mechanisms are fatigue wear, abrasive wear, and oxidative wear. Deposition of C₃N₄ coating conforms to the polarization-adsorption-electrochemical reaction mechanism in the present investigation conditions.