Tribological parameters of the frictional contact in the cutting tool material being machined are very important for choosing an optimal tool material and wear-resistant coating. The paper considers an experimental technique that allows experimentally simulating with a high degree of reliability the real conditions of friction and wear at the local contact of a tool and a workpiece in the cutting zone when exposed to the appropriate temperatures (400-800 °C). This technique makes it possible to determine parameters such as the strength  n of adhesion bonds on the cut and the adhesion (molecular) component f M of the friction coefficient. Special equipment has been developed that makes it possible to heat the contact zone and provide a typical temperature distribution through the depth of the contacting bodies. The use of the described technique facilitated obtaining data on the influence of temperature on the tribotechnical properties of tribopairs of coated cutting tool material being machined for various grades of the material being machined and the coating compositions. These results were compared with the data of the corresponding cutting tests.

The article describes the results of an investigation focused on the properties of the Ti-TiN-(Ti,Cr,Mo,Al)N multilayered composite coating with a wear-resistant layer of nanolayer structure. A transmission electron microscope was used to study the coating structure. The examination of the phase composition using selected area diffraction electron pattern has detected the presence of two phases, including c-(Ti,Cr,Mo,Al)N and h-AlN. The cutting properties of the tool with the coating under consideration were studied during the turning of AISI 1045 steel at vc = 300 m/min, f = 0.25 mm/rev, and ap = 1.0 mm. After 16 min of cutting, the wear rate for the tool with the Ti-TiN-(Ti,Cr,Mo,Al)N coating was 1.9 times lower compared to the wear rate for the tool with the (Ti,Al)N commercial monolithic coating. As a result of the investigation focused on the fracture pattern on the coating during the cutting, the brittle nature of the fracture has been detected with a noticeable effect of adhesive fatigue mechanisms.

The study proposes a model for the deposition of coatings, which takes into account the stochastic nature of the deposition process and is built considering the influence of the parallel convection and diffusion processes. The investigation has found that the dispersion of the motion direction of deposited particles in front of a substrate increases, which indicates a growth of the randomness in the trajectories of the particles being deposited. The obtained formulas indicate the fractal nature of the deposition process. During the formation of the multilayer coating structure, mismatched fractal structures of the layers overlap each other and thus the clustering effect is largely leveled out. The value of the nanolayer λ period has a significant influence on the fractal structure of the coating and the formation of feather-like hierarchical structures in it.