Analysis of the current density and electrolyte composition influence on the quality of micro-arc coatings

Abstract

The results of an experimental study of oxide coatings obtained using an automated system developed by the authors in the anode-cathode mode at a ratio of the anode current to the cathode current equal to 1, at low current (0.125 A or 0.25 A) with different electrolyte composition are presented. An analysis of the dependence of the quality of the obtained coatings on the molding curves, which characterize the change in the electrical voltage on the samples depending on the time of their processing was made. It has been established that with increasing current density, the process is more intense, microdischarges begin to burn earlier, and, in general, the coating quality increases. However, at too high current densities (50 A/dm2), it is undesirable to carry out micro-arc oxidation treatment due to an increase in the coating roughness. In particular, it is expedient to use the results obtained for quality control of the technological mode under production conditions: the coating has inadequate quality if the molding curve has a distorted shape. The results obtained have been tested in the implementation of the method of formation by microarc oxidation of oxide coatings with specified properties.