INVESTIGATION OF THE ELECTROLYTE EFFECT ON VN CREATED VIA PES

Abstract

One of the most important methods of hardening steel tools is nitriding. During this process, nitrogen diffuses into the sample surface at high temperature and reacts with the elements existing in the sample and creates hard nitrides. Another way to create hard nitrides is the simultaneous hard diffusion of two nitride-causing elements. During the plasma electrolytic saturation process, one nitride –causing element, together with nitrogen, diffuses into the surface of the sample and forms a hard nitride coating on the surface of the component. In this process, a voltage is applied between a cathode (sample with smaller surface) and an anode (sample with larger surface); the plasma is formed on the surface of the cathode which then let the given elements diffuse into the surface of the base metal. In the present study, nitrogen and vanadium have diffused into the surface of the sample, 1.2436 tool steel, and vanadium nitride has been formed. The best combination of electrolyte solution is 4g Ferro vanadium, 50±1 ml nitric acid and sodium hydroxide. The results is indicating that the formed coating layer thickness is about 2-3.5 μm. As the conductivity increases, the condition for diffusion is provided; however, with over increasing the temperature, diffusion decreases. The coating formation has observed in 7-10±0.5 A current.