The article addresses the relevant issue of reducing the coefficient of friction under dry contact conditions between surfaces of mechanical components by optimizing surface roughness parameters. Based on an analysis of current research in the field of tribology, it is established that traditional approaches focused on lubrication are not effective or feasible in several high-tech processes such as vacuum metallization, application of functional coatings, and others. Therefore, the search for methods to reduce friction under dry contact conditions is particularly important for improving the durability and energy efficiency of technical systems. The study focuses on the development of a mathematical model that considers both the elastic deformation of surface microasperities and the adhesive interactions arising in the contact zone. To describe the bending of microasperities, a plate bending equation is used, while the Hertzian contact model is applied to describe the contact interaction. As a result of numerical modelling, it is shown that the coefficient of friction significantly depends on the surface roughness height (Ra) and average spacing (Sm), as well as on the material properties that determine their elasticity and adhesive behaviour. It is found that with changes in the geometric parameters of microasperities and the properties of the materials, the coefficient of friction can exhibit both increasing and decreasing trends. Of greatest engineering interest is the identification of a clearly defined minimum of the friction coefficient for a specific combination of surface roughness parameters and material characteristics. This creates opportunities for the intentional design of surface finishing technologies aimed at achieving optimal frictional performance without the use of lubricants. The article provides graphical dependencies illustrating the behavior of the friction coefficient as a function of surface parameters and adhesion level. The theoretical conclusions presented can be used to determine optimal roughness values when designing and manufacturing machine parts that operate in vacuum, biomedical devices, or environments with limited lubricant access. The authors also emphasize the need for further research aimed at determining the coefficients of adhesive interaction (k₁ and k₂), as well as refining the role of the actual contact area, which may significantly affect the frictional force.
Riabchykov et al. (Thu,) studied this question.