A Phenomenological Model of Nanocrystalline Coating Production Using the Plasma Electrolytic Saturation (PES) Technique

Authors

1 Faculty of Engineering,University of Tehran

2 Department of Chemical Engineering,Isfahan University of Technology

Abstract

Abstract. The Plasma Electrolytic Saturation (PES) technique is a relatively new process, which
uses a high DC voltage power supply with a related organic electrolyte. Within the phenomenological
model, the mechanism of the nanocrystalline coating formation processes has been developed to clarify the
controlling variations of the procedure. Within the informative model, a feedback parameter for the formed
surface state estimation was established. This parameter is the power spectral density of the current. The
voltage versus current characteristics of the treatment within the plasma region depend on the main
electrolysis conditions, such as current density, electrolyte concentration and agitation rate. Application
of the control algorithm of the parameters could increase the eciency of the plasma electrolytic saturation
and nanocrystalline coating formation. In this process, the electric eld strength, E", within the surface
region reached a value of between 106 and 108 V/m, which was sucient for initiation of ionization
processes in the vapor envelope. The ionization phenomena initially appeared as a quick sparking in
scattered gaseous bubbles and then transformed into a uniform glow distributed throughout the vapor
plasma envelope. Because of the hydrodynamic stabilization of the vapor envelope in the region of 180-
210 V, the current dropped and the glow discharge transformed into intensive arcing, accompanied by a
characteristic low-frequency acoustic emission.

Keywords