Fabrication and Triboengineering Properties of Aluminum Composite Ceramic Coatings

Abstract

The paper presents the basics of the technology for fabrication of solid lubricant composite ceramic coatings that are basically a ceramic matrix with antifriction fillers based on magnetite, graphite, and molybdenum disulfide, which are formed on the aluminum alloy using the micro-arc oxidation method. It also shows the features of electrophoretic implantation of dispersed particles of magnetite, graphite, and molybdenum disulfide into a ceramic matrix. The authors have experimentally studied the dependence of coating triboengineering properties on the concentration of solid lubricant particles in the electrolyte and temperature conditions in the friction zone. As a result, they have formed the requirements for the composition of the electrolyte used to apply these coatings. The comparative triboengineering tests have shown that synthesized solid lubricating composite ceramic coatings with antifriction fillers have higher antifriction characteristics, a lower friction coefficient, and are more wear resistant compared to unsupported ceramic materials obtained by a traditional technology of anodic spark oxidation. The new synthesized coatings can improve antifriction characteristics of friction surfaces for units operating in the absence of a lubricant by several times. The wear analysis of the obtained coatings has shown that the obtained ceramic coating with the molybdenum disulfide as a filler has the highest antifriction properties. The triboengineering tests of molybdenum disulfide coatings (as a solid lubricant) confirmed the need for the adsorbed protective films on the dispersed phase particle surface during the microarray application of these coatings to improve antifriction properties of the particles.