DETERMINING THE DIMENSIONS OF DISCRETE COATING SECTIONS FOR TOOLS USED IN POLYMER COMPOSITE MACHINING

Abstract

Improving the wear resistance of cutting tool working surfaces is a key factor in ensuring their long service life during the machining of complex materials, particularly polymer composite materials (PCMs). One promising direction is the development of discrete coatings with a special microstructure, which not only provide high hardness and wear resistance but also ensure optimal distribution of the stress–strain state (SSS) in the subsurface layers of the tool. To date, no studies have been conducted on the use of discrete globular-structure coatings applied by electro-spark alloying to high-speed steel cutting tools for machining polymer composites. This type of surface architecture has the potential to reduce residual stresses, prevent cohesive cracking of the coating, and mitigate the formation of cracks that shorten tool life.Under high dynamic loads during polymer composite machining, the use of continuous protective coatings is questionable due to their susceptibility to cracking caused by thermal fluctuations and localized deformations. In contrast, discrete coatings allow for more uniform stress distribution, localization of damage in specific areas, and prevention of its propagation across the entire surface. It is important to note that the geometry and dimensions of individual discrete coating elements have a decisive influence on the formation of residual stresses, the nature of contact with the workpiece material, and the overall cutting efficiency.This article emphasizes the need to develop a scientifically based approach to determine the optimal sizes and shapes of discrete protective coating elements, taking into account strength requirements, durability, and the feasibility of the coating process. Such an approach should consider the influence of coating parameters on the SSS, considering the specific working conditions of tools used for PCMs, which are characterized by high abrasiveness, low thermal conductivity, and a tendency to adhere to the cutting edge.Conducting the appropriate research will help formulate recommendations on the rational architecture of coatings that ensure improved tool durability and stability of machining parameters. Ultimately, the implementation of discrete coatings with controlled geometric characteristics opens up new opportunities for creating efficient tools designed for high-performance machining of polymer composites with minimal wear and repair losses. To address the issue of developing a modified surface layer architecture for cutting tools, an approach must be developed to determine the dependence of the coating’s SSS on the size and shape of the discrete coating elements.