No 8 (158) (2024)

The article views fundamentally different scientific approaches to the study and processes control for metallopolymer friction units tribocontacts and, separately, for metal ones. The article presents the developed criteria for the choice of fillers in the composite: for example, in antifriction interfaces, it is a mechanism that forms secondary structures (friction transfer films); in friction interfaces, it is the introduction of reinforcing elements into a polymer composite, that, as a result of friction, can penetrate into the metal counterbody and strengthen it. At the same time, the strength characteristics were evaluated by quantum chemical calculations and experimental confirmation by X-ray electron and Auger electron spectroscopy (AES) data. As for the wear resistance increase in metal-to–metal tribosystems by traditional methods – electric arc metallization, gas-flame coating, detonation-gas, plasma, etc., they do not properly ensure stable operations of tribosystems. Currently, the most promising techniques used for surface modification and hardening are vacuum ion-plasma technologies. The ideas of applying thin-film coatings are based on techniques based on both physical processes (physical vapor deposition with PVD coating) and chemical principles (chemical deposition from the gas phase – CVD process). The PVD- method involves the transfer of the coating material to a vaporous state, followed by its delivery to the sample and vapor deposition on it. When using CVD methods, the coating on the sample is transferred from carbonites, organometallics, etc. The paper presents the results of research for finding the dependence of the physico-mechanical and tribological properties of coatings –PVD, DLC, high-entropy or combined, on the technological parameters of application.

The problem of rational design of the structure, manufacturing of shape-generating molding tools made of polymer composite materials and its use in forming thin-walled composite structures by vacuum infusion is viewed. Taking into account the requirement of minimum deformations of warping of the molded composite structure caused by residual stresses as a result of polymerization of the binder, the necessity of creating such equipment in two stages is justified. This implies both: a master mold making on CNC and producing the most open composite mold used for molding finished structures. Using the example of a thin-walled aircraft structure of complex geometry, the possibility of obtaining a process scheme and controlling the modes of manufacturing a composite mold and a part molded on it applying a developed computer modeling tool, that uses experimentally determined characteristics of components (reinforcing glass, carbon fabrics, thermosetting resins) and CAD models of the molded structure as initial information, is shown. The necessary experimental equipment, experimental technique and data processing to obtain the dependences of compressibility and permeability on the degree of binder filling of composite molds, and also on the ratio of externally applied compression and internal pressure, are viewed evidence from an 8-layer fiberglass preform T-10-14. For the consistent description of the viscosity of thermo-reactive resins, which evolves within the process and depends on temperature, degree of polymerization and time, a semi-empirical model is proposed, the parameters of which can be found in an empirical way by methods of differential scanning calorimetry and rheometry. The use of the developed computer modeling tool to maximize the level and equalization of the specific volume of the reinforcing component in the body of the molded structure, reducing the duration of the vacuum infusion process is illustrated by the example of three strategies for controlling external compression and vacuum pressures.

It has been suggested that wave technologies in non-rigid plane parts production should be used with the introduction of ultrasonic range vibrations into the shaping zone in combination with technological equipment, i.e. it is- a zero-base system. The traditional technique used in domestic enterprises implies a high probability of out-of-flat conditions and deformations due to the influence of technological residual stresses (TRS) in the process of stock removal or force stresses under plastic deformation of the part when fixing blanks. Using modern universal software systems such as Simulia Abaqus, ANSYS, etc., it was possible to determine the magnitude of deformations, aligment errors caused by residual stresses. The data obtained were used to calculate rational ways for fixing some typical non-rigid plane aluminum blanks on a technological equipment - a zero-based system of German production SCHUNKVERO–SAviation (VSA). The research was aimed at determining the manufacturability for the use of such equipment when making a particular non-rigid blank made of aluminum alloys and finding the most optimal way of its fixing. The estimated values of the TRS were determined by mechanical and X-ray methods. The calculations were performed using real parts of aircraft equipment of the "beam" type and blanks made of aluminum rolled products. The proposed method for determining the maximum amount of deformation of the workpiece under machining is applicable to the most optimal placement of the support and clamping modules of the zero-based system (VSA). In combination with a certain strategy of wave mechanical processing, it makes a practically complete compensation for deformations possible and allows obtaining a suitable product from the first presentation without performing an additional correction operation.

A review of the technologies of vacuum ion plasma (VIP) coating spraying based on the reasonability of science intensity, its criteria and evaluation methods is carried out. The technological features of producing VIP coatings are viewed with the emphasis on the process of coating formation on a substrate, which occurs under the impact of the most powerful forces in nature, i.e. these are forces of interatomic interaction. This leads to a very high level of cohesive strength of the coatings, which results in wear resistance and corrosion resistance. This leads to a very high level of cohesive strength of the coatings, succeeding in wear and corrosion resistance. Methods of research, diagnosis and testing of VIP coatings, due to the peculiarities of their structure and properties, include, as a rule, equipment and techniques of leading world manufacturers in the field of electron microscopy, microrentgen spectral analysis, diffraction analysis, X-ray photoelectron spectrometry, continuous and dynamic indentation, bench testing of unique properties. With respect to scientific and practical activities of the authors, examples of coatings of various nature (nitride, carbon, metalloceramic), different architectures (monolayer – single-phase, multilayer – 2D composites, dispersed – 3D composites) and various applications (wear–resistant, tribotechnical, antierosion, thermal barrier) are given. In particular, some types of nitride coatings TiN, TiAlN, CrAlSiN, which are characterized by high hardness H  24 GPa and abrasive wear resistance, are in the focus. However, in conditions of relatively smooth sliding friction, only the multiphase nanostructured CrAlSiN coating retains wear resistance. In conditions of drop-impact erosion, nanocompositional multilayer VIP coatings of TiN/MoN composition demonstrate the highest resistance, which compete with the recognized champion in this field - welded plates of stellite VZK (WCoCr). Despite the fact that the thickness of the VIP coatings viewed in the paper is a film of 1...10 microns, whereas the stellite plates have a thickness of at least 4 mm. In conclusion, it is noted that VIP technology continues to develop new materials, for example, to create diamond-like coatings or coatings made of high-entropy alloys. VIP technology corresponds to a high level of science intensity, and VIP coatings are promising for putting to use in mechanical engineering.

Digitalization aspects of the production process at a machine-building enterprise related to production design and control for machining operation in the cutting process, are viewed. The review of ways for machine-building production upgrading through the introduction of digital technologies, is given. The connection with the targets of the state industrial and innovation policy, as well as with the development programs of the country's leading scientific and industrial corporations, is shown. The content of the concept of a digital production system is given. The importance of having an array of complete and reliable technological information for the production process control automation at a machine-building enterprise is emphasized. The necessity of the upgrading in planning for machining industries connected with the introduction of digital production systems, as well as cutting process control for stability and quality is shown. Work in this direction makes it possible to create conditions for organizational, informational and technical compatibility of the activities aimed at the operational analysis, carried out by various performers, to implement interaction of all the stages for launching into manufacture and production work and to ensure the stability of flow processes in the machining operation. The principles of operational analysis in the implementation of digital production systems, are formulated. It is shown that the use of digital technologies in the operation of the technological system delivers stable operation of cutting tools, as well as the quality of manufactured products in conditions of stochastic and non-stationary nature of machining operation, providing an increase in the values of versatility indicators for reliability and technological systems utilization efficiency. The problems and directions of promising digitalization upgrading for the production process at a machine-building enterprise, are specified.