The influence of the microrelief of the metal surfaces of the substrate on the adhesive properties of meta-aramid coatings

Abstract

Purpose. In order improving the tribotechnical properties of the surfaces of parts, a progressive method is the application of a polymer coating on a relatively cheap metal material. When choosing polymers for use in friction nodes, it is important to evaluate their properties, namely strength, heat resistance and wear resistance. In the technological process of applying coatings, the adhesion of polymers is a significant characteristic. The condition of the surface of the substrate and the viscosity of the polymer material should be attributed to the conditions affecting the formation of the adhesive contact. The purpose of this work is a detailed study of the influence of the nature and microrelief of the surface of the substrate on the adhesion ability of meta-aramid itself. The methods. To achieve the goal, a coating was applied to metal plates made of carbon steel St3 and copper alloy M1, the roughness of the surfaces of which was changed with the help of abrasive grinding wheels. The starting material of the coating in the form of a finely dispersed powder was dissolved in dimethylacetamide. A coating with a thickness of 80...100 μm was formed by applying a solution of meta-aramid on the surface of a metal substrate, followed by evaporation of the solvent in a drying cabinet at a temperature of 150...160ОС for 45...50minutes. To determine the strength of the adhesive joint of the meta-aramid coating from the surface roughness of the steel and copper substrate for different concentrations of the polymer solution, mathematical processing, approximation and extrapolation, experimental data were carried out in the work. Findings. The influence of the microrelief of the surface of metal substrates and the viscosity of the polymer solution on the adhesion ability of meta-aramid coatings was investigated. The optimal parameters of the roughness of the substrate and the concentration of the polymer solution were determined using the method of mathematical modeling. The originality. The relationship between adhesion indicators and the roughness of metal surfaces has been established. It helps to form recommendations regarding the parameters of the surface roughness of the substrate to ensure adhesion of the coating. Practical implementation. The application of polymer coating technology allows to increase the performance of parts in friction nodes, using relatively cheap metal materials for their manufacture. The obtained results form recommendations regarding the roughness parameters of the substrate surface and the concentration of the polymer solution.