Peculiarities of heat transfer at anodic plasma electrolytic treatment of cylindrical pieces

Abstract

Heat transfer in a three-phase electrochemical system consisting of a metal cylindrical anode (a workpiece), a vapor-gas envelope, and an electrolyte solution is considered. The purpose of the study is to determine the effect of the length of the sample part contacting with the electrolyte on the distribution of the heating characteristics on its surface. It is established that the increase of the length of the part of the anode submerged into the electrolyte causes a decrease in the average current density, reduction in the vertical current density gradient, and a decrease in the density of the heat flux from the envelope to the sample. A model is proposed to calculate the stationary cylindrical anode temperature and the current in the system with the evaluation of the convective heat flux from the anode portion protruding above the electrolyte into the atmosphere. The influence of the electrolyte flow along the sample on its temperature and the average current density in the system is determined and attributed to the variation of the vapor-gas envelope thickness.