FEATURES OF COATING LAYERING BY THE MICRO-ARC OXIDATION DURING NANOALLOYING

Abstract

The use of coatings with increased tribotechnical characteristics in the microarc oxidation process with nanoadditives is a promising direction for improving the operational properties of parts and assemblies. (Research purpose) The research purpose is evaluating by mathematical and experimental studies the optimal modes of the microarc oxidation process when applying nanoadditives to the electrolyte. (Materials and methods) The article presents the regularities and limits of the concentration of additives in the electrolyte by mathematical modeling based on the theory of solid state physics for semiconductor materials. Experiments were conducted with various additives both in chemical composition and concentration to confirm mathematical conclusions. The anode-cathode method of conducting the microarc oxidation process with similar modes for all experiments was used. (Results and discussion) The introduction of elements of a non-valve group of metals as additives leads to the termination of the microarc oxidation process when a certain concentration of additives in the coating is reached. The results of an experimental study of the microarc oxidation process during the introduction of nanopowders into the electrolyte were presented. Compound additives to the electrolyte whose oxides do not have semiconductor properties limit the thickness of the coatings up to 60 micrometers. The introduction of copper and vanadium compounds into the coating can lead to a decrease in the friction coefficient and a decrease in wear in friction pairs. (Conclusions) The article describes the mathematical model for predicting the growth rate of the coating during nanoloading for an out-of-pocket microarc oxidation method. Compound additives to the electrolyte whose oxides do not have semiconductor properties limit the thickness of the coatings up to 60 micrometers. The most technologically advanced nanoadditives are compounds that have good solubility, for example, sodium tungstate.