Moscow State Technological University

Working in aggressive environmental conditions and the interaction of friction pairs place increased demands on modern parts used in the aircraft-engine industry, electric-power industry, and medicine. Often, working in such conditions leads to premature failure of parts and equipment, as well as energy losses due to friction and wear processes. Modern technologies for surface modification and coating by various methods can improve the performance of such parts. The technology of laser surfacing of wear-resistant coatings in combination with preliminary surface modification makes it possible to create a protective layer on the surface and strengthen it. This article provides an overview of modern methods of surface modification and protective coating using various physical technologies, highlighting their advantages and disadvantages. The most promising method is laser surfacing of wear-resistant coatings with preliminary surface modification. An algorithm of the laser surfacing process has been developed for this technology. It is proposed to use a new wear-resistant coating of powder materials based on chromium and molybdenum carbides. The effect of the mixture composition on the properties of the synthesized coating is determined. The adhesive strength and thickness of the coating were evaluated.

This article presents an application of the YOLOv8 model to the automated detection of surface defects in mechanical engineering products during industrial research using additive manufacturing of metals. The article discusses the dataset formation, the model training process, and the results of applying the proposed solution to automated quality control of mechanical engineering products manufactured using additive manufacturing.

As set out by A.A. Ilyushin and I.A. Kiiko, a boundary value problem of plastic flow in a thin layer enclosed between two approaching surfaces of elastically deformable bodies of the tool is formulated. For the case of the Winkler model of an elastic body, a solution to the axisymmetric problem of the compression of a plastic layer in the ring-shaped area is written out in analytical form.

The article examines the stability of soliton-like solutions of the nonlinear Schrödinger equation with two types of nonlinear dependence of the dielectric constant on the electromagnetic-field strength. A multilayer structure of dielectric media obeying Kerr’s law and the saturation effect is considered, taking into account the absorption of part of the incident radiation by the medium. Numerical modeling is carried out to study the occurrence of the phenomenon of optical bistability and stability of wave propagation depending on the type of optical nonlinearity of the material.

To reveal the damage and material removal mechanisms of SiC ceramics during laser-assisted grinding, molecular dynamics simulations were conducted. The effects of grinding force, coefficient of friction (COF), stress distribution, subsurface damage, and abrasive wear were systematically investigated. The results revealed that the damage mechanisms in laser-assisted grinding of SiC ceramics primarily involved stress-induced amorphization transitions, dislocations, stacking faults, and vacancies. As the laser power density and laser radius increased, the extent of amorphization transition intensified, leading to improved grinding quality and reduced COF and abrasive wear. However, excessive laser power density induced thermal damages and deteriorated the surface/subsurface quality. In addition, a smaller grinding depth and a higher grinding speed effectively delayed the abrasive wear.