PROSPECTS FOR CREATING SURFACE LAYERS OF DETA-LEU WITH INCREASED TRIBOLOGICAL CHARACTERISTICS USING GAS-DYNAMIC FILLING

Abstract

The article presents the results of the analysis of antifriction materials based on tin and lead, copper, aluminum, plastics. The advantages and disadvantages of one or another antifriction material, as well as the possibility of their application on the surface of parts by the method of cold gas-dynamic spraying, are shown. The use of liquid and solid anti-friction materials as lubricating oils is considered. Considerable attention has been paid to materials with the same crystal structure as graphite, now known as two-dimensional (2D) materials. Among these 2D materials, the most studied materials are MoS2 and a carbon-based compound, including graphite and graphene. The scheme of interaction of sliding surfaces is considered, including wear, molecular deformation, adhesion, thermal effect and the environment. Analysis of anti-friction materials showed that their application to the surface of parts can be carried out using the process of cold gas-dynamic spraying. The article shows a diagram and type of installation for cold gas-dynamic spraying of antifriction surface layers. For the research, copper-graphite powder with a particle size of 10,7 – 80,8 microns was used. Using the application "Maso central characteristics" of the software "Compass-3D", the mass of the deposited figure as a continuous material for copper-graphite coatings, with a density of ρ1 = 0,0086454 g / mm3, and the porosity of the deposited figure were determined. In the course of the study, it was found that, in comparison with the substrate material AA7075, the sliding friction coefficient was reduced by 47% - 62% for the copper-graphite surface layer. To obtain composite coatings, a mechanical mixture of A30-01 aluminum powder and C01-00 copper was used. The dependences of the coefficients of sputtering of copper and aluminum on the mass content of aluminum in the sprayed mixture at an initial concentration of aluminum of less than 66% are found. The copper deposition rate is higher than the aluminum deposition rate. Both monotonically increase with increasing aluminum concentration until it reaches 61%. At high concentrations of aluminum (more than 66%), the coefficients of deposition of copper, aluminum and their mixtures coincide.