No 4 (166) (2025)
Additive technologies and laser processing
INDUSTRIAL INSTALLATIONS FOR ADDITIVE MANUFACTURING, MANUFACTURED AT THE MOSCOW CENTER FOR LASER TECHNOLOGIES
Abstract
The decade-long period of the evolution starting from the first installations to a modern complex, designed and manufactured entirely using just indigenous content, including software and an optical system, is presented. The first SLM-110 installation, manufactured in 2016, had a construction volume of 110×110×200 mm. Over the years, numerous research projects have been carried out. They served as the basis for the development of technological processes for growing parts and units obtained from various metal powders. In subsequent developments, the volume of grown products was increased to 250×250×300 mm. As a result of the completed R&D, a more advanced SLM-250 installation was designed and manufactured. In this installation with a sensor system a full automatic monitoring and control of process parameters is provided for long-term continuous operation of the complex for many days, ensuring high reliability and stability. A number of plants are successfully used in our industry in the production of complex products from a variety of metal, ceramic and composite powders produced in our country. The next stage in the development of additive manufacturing is the organization of sites for the manufacture of parts based on additive complexes and peripheral equipment. It is necessary to organize serial production of existing installations in our country and develop equipment to increase the process performance
Science intensive technologies in mechanical engineering. 2025;(4 (166)):3-7
3-7
MATHEMATICAL MODELING IN ADDITIVE TECHNOLOGIES USED FOR TOPOLOGICAL OPTIMIZATION
Abstract
Additive technologies exemplified well in the industry. As a rule, it is technologies called synthesis on a support material (selective laser melting and the like), that make it possible to create products with complex geometries, internal channels, etc Modern software allows significant expansion in the capabilities of such technologies. One of the directions of the development in this area is the generative artificial intelligence, for example, in case of topological optimization aimed at reducing the weight of the product without loss of strength characteristics. It is based on well-known mathematical models and numerical calculation methods. At the same time, it has now become possible to calculate several models in parallel, depending on the set parameters. At the moment, several algorithms are used for modeling and calculations, gaining the reputation of good results, but at the same time an additional verification of the results obtained before manufacturing, is required. This paper presents the main mathematical models and examines the features for optimization in additive technologies. It discusses examples of model combinations. Using the example of a promising optimization method, the existing limitations and the possibilities of overcoming them are studied. Due to the peculiarities of modeling, one of the tasks is to obtain the results closest to the real ones, therefore, an option for improving the work is proposed, taking into account the real values of experiments. A pattern to understand the specifics of the work of various methods is given, allowing a possible data calculation option depending on the available initial conditions.
Science intensive technologies in mechanical engineering. 2025;(4 (166)):8-16
8-16
Technologies of mechanical processing of workpieces
THE IMPREGNATED ABRASIVE TOOL POTENCY IN MECHANICAL TOOLING OF BEARING PARTS
Abstract
The technology of grinding bearing parts holds a significant place in machinery production. This topic is particularly relevant at the present time, as there are raised requirements for this process, both in terms of productivity and the quality of finished products. The efficiency of finishing bearing parts in modern high-tech manufacturing is determined by the use of highly efficient abrasive tools with stable performance characteristics. Ceramic-bonded abrasive tools are subject to significant environmental effects, especially when working with water-based cooling lubricants (coolants), which significantly alter the physical and mechanical properties of grinding discs, reducing its hardness and strength and, resulting in a decrease in its performance characteristics. One of the effective ways to improve an abrasive tool can be considered the introduction of solid lubricants (impregnation) into its pores, which improve the grinding conditions and the quality of the surface layer of the machined bearing parts. The laboratory studies carried out by the authors on the basis of the Scientific and Technical Center "VNIIASH" and considered experience of industrial use of impregnated tools in bearing manufacturing enterprises show its effect only in the case of uniform impregnation of the entire abrasive tool and ensuring uniform filling of its pore space. Based on the results of our research, we have found the possibility of productive, high-quality impregnation of abrasive tools with sulfur using the method of free capillary ascent along the pores of the disc. The use of impregnated abrasive tools at the enterprises of the EPC corporation makes it possible to improve the quality of processing bearing parts and reduce the consumption of abrasive tools by 1,1 – 1,8 times.
Science intensive technologies in mechanical engineering. 2025;(4 (166)):17-23
17-23
TECHNOLOGY AND RESULTS OF STUDYING THE DIVERSIFICATION OF THE OPERATIVE CONDITIONS OF METAL CUTTING TOOLS
Abstract
The technology and the results of its investigation contributing to studying the diversification of the operative conditions of metal cutting tools, are presented as exemplified in a tool equipped with a hard alloy plate. It is shown that the rate of diversification can be judged by the appearance of a two-dimensional histogram constructed from time series of signals indicating fluctuations in the technological system in mutually perpendicular planes. The occurrence of a "comet tail" pattern on the histogram indicates a high rate of diversification of operative conditions, in particular, during the running-in of the tool. To show the dynamics of the diversification, a cross-correlation curve is used, the form of which characterizes the strength of the relationship between the directions of oscillation. This networking proves regulation of operative conditions and the transition to a starting operation in a stationary mode. Diversification dynamics is identified using a procedure based on statistical test of the hypothesis for the significance of changes in the transformation coefficients of the spectra of diverse oscillation signals using the Student's t-test. The identification results showed that state diversification dynamics is a change in connections and constraint in the industrial process system, which leads to the formation of new dynamic properties that reduce cutting forces due to the redistribution of friction forces between the front and rear surfaces of the tool and, as a result, increase stability for disturbance resulted from the operating procedure. The approach used in the development of the process desigh is compared with approaches based on the construction of a mathematical (analytical or stochastic) model of a real system. The direction of practical implementation of the technology in the software of CNC systems is justified for more efficient solution of traditional control tasks, in particular, process tasks, which will ensure an increase in the reliability of the tool.
Science intensive technologies in mechanical engineering. 2025;(4 (166)):24-31
24-31
Technological processes automated control
HIGH-TECH TECHNOLOGIES FOR THE IMPROVEMENT OF THE PRODUCTIVITY AND RELIABILITY OF MECHANICAL ENGINEERING PRODUCTS
Abstract
Economics evaluation method of high-tech technologies application for part process of various purpose made of hard-to-machone steel or alloys at machine-building enterprises is presented. It is shown that the overall economic effect of using high-tech technologies in production processes consists of direct and additional effects. Direct benefits can be obtained by optimizing the modes and changing the conditions of machining parts, increasing the durability of the used metal-cutting tool and improving the manufacturing system as a whole by increasing its reliability and vibration resistance. To achieve direct benefits, it is proposed to use iodine-containing agents in the machining parts processing procedure and metal-cutting tool sharpening, as well as the supply of cooled ionized air both to the contact zone of the tool and the surface of the part. Additive effect can be obtained both by improving the quality of the machined surface of the part, and by perfecting organizational and technological measures during repair work, maintenance and routine maintenance within the operation of mechanical engineering products. The main components of the additive economic effect are viewed and the technique for their determination is given. Based on the analysis of the developed technique for the economics evaluation for high-tech technologies in part process together with its testing at a number of machine-building enterprises, the authors prove that its use provides calculated data comparable to the actual benefits, and can be applied in any type of production, including machine maintenance.
Science intensive technologies in mechanical engineering. 2025;(4 (166)):32-39
32-39
Science intensive technologies in coating, parts repair and recovery
ELECTROCHEMICAL GRINDING OF GALVANIZED ELECTRICAL CONNECTORS FOR THE RAISE OF STATIC COEFFICIENT OF FRICTION IN THE CONNECTION
Abstract
Galvanic coating of electrical connectors is viewed. It was established that the existing electroplating technologies ensure the surface quality that was obtained on the support material. Using the example of galvanic nickel plating on a copper support plate, a method for improving the quality of the nickel-plated surface layer is proposed. It is proposed to use electrochemical grinding as an additional technological operation. Alternating electrochemical grinding and galvanic nickel plating will make it possible to obtain a higher-quality nickel surface layer, which will allow for a larger area of actual contact in the connection. This, in turn, will increase the static coefficient of friction and the reliability of the electrical connection during vibrations. The presented surface will provide a minimum number of cracks, deep scratches and dents on the product, which in turn increases electrical conductivity, surface compound of the contact electrical connectors, and also reduces the electrical resistance that occurs when interconnection.
Science intensive technologies in mechanical engineering. 2025;(4 (166)):40-48
40-48