Metalloobrabotka № 5-6 (125-126)/2021

Metal cutting

Mokritskiy B. Ya. A tool for milling workpieces with high hardness surfacing

The features of surfacing processing with milling cutters of different designs are investigated. Criteria for evaluating the effectiveness of milling cutters have been developed. The most effective milling cutters have been determined. It is established that the processing of these surfacings by milling is possible without compromising the quality of the treated surface, but the share of tool costs per unit volume of surfacing material is different for different cutters and is related to the conditions of surfacing. The performed studies have shown different possibilities of using milling cutters for processing blanks of parts, the hardness of the material in the upper deposited layer of which reaches a hardness of 51 Rockwell units. The dependence of the durability period on the milling conditions and the parameters of the cutting mode is established. The most rational milling cutters and cutting mode parameters are recommended.

Keywords: milling of solid materials, selection of competitive milling cutters in terms of durability period, optimization of cutting mode.

Alexandrov A. S., Petrov V. M., Sharko E. A. The study methodology of machinery using polymer composite materials cutting and parameters estimation of surface layer quality parameters

The growth in the production of polymer composite materials with valuable and sometimes unique properties requires an increase in the volume of mechanical processing. It is an obligatory, most responsible and most time-consuming operation in the technological cycle of production of PCM products. This article analyzes the machinability of parts made of polymer composite materials (PCM) with lathe plates from Virial made of tool material based on tungsten carbide VHS1013. Knowing the features of the material being processed, you can choose the most profitable processing strategy by following the algorithm specified in the work.

Keywords: polymer composite materials, quality, wear, anisotropy of properties, fibers, matrix

Vasilkov D. V., Cherdakova V. S., Golikova V. V., Rak A. A. Development and parameterization of a dynamic model of a technological machining system based on a rheological approach

A brief review of research in the field of self-oscillations during cutting is presented. The applicability of the rheological approach to the study of the dynamics of technological systems of mechanical processing is substantiated in order to develop and parameterize the corresponding nonlinear dynamic model. A non-linear dynamic model of a piecewise linear type in the space of generalized coordinates is proposed, in which the features of contact interactions from the front and rear surfaces of the cutting tool are considered and the function of switching between the sliding and setting phases is implemented, which simulates the formation and breaking of adhesive bonds in the cutting zone. A transition to the space of variable states was made, which made it possible to reduce the order of time derivatives and form a vector-function of a piecewise linear type for the sliding and grasping phases with self-organization of switching between them. The parameterization of the dynamic model was performed using modern modeling methods. The presented nonlinear model of a piecewise linear type makes it possible to investigate the level of oscillation amplitudes, which is the basis for modeling regulated quality parameters during machining.

Keywords: technological system of mechanical processing, dynamic model, rheological elements, non-linear system of piecewise linear type, slip, grip, switching function, generalized coordinates, state variables, parameterization of dynamic model.

Metal forming

Kuznetsov P. A., Tretyakov V. P., Prostorova A. O. Technology of joint pressing of bimetal products from powder and sintered materials

A new technology of joint pressing of bimetallic products from sintered and powdered materials is presented. The existing processes of joint pressing of powders are analyzed in order to obtain bimetallic materials and expand the range of bimetallic sintered products. A technology is proposed for joint pressing of powder and sintered elements as part of a bimetallic product are proposed. The preliminary manufacture of sintered working elements ensures the production of bimetallic products from dissimilar powders with a significant difference in their technological characteristics. The technology was carried out by pressing standard products in molds — bimetallic discs, bushings and cups. It is shown that this technology has a low cost due to the simplicity of molds and the possibility of its implementation on universal equipment.

Keywords: powder pressing, bimetals, sintered products, layered composites, strength of bimetallic compounds.

Electrophysical and electrochemical processing methods

Pimenov V. A., Reva V. P., Andreev V. V. Study of the method of electric pulse plasma sintering of ceramic materials of the Primorsky krai with mechanoactivated additives

The article discusses the relevance of using electro-pulse plasma sintering for local raw materials, shale and quartzite deposits of the Spassky Primorsky Territory. This research is promising and aims to meet the market demand for ceramic products from local raw materials. The presence in the Primorsky Territory of a deposit of mineral raw materials, which can serve as the basis for the creation of the production of ceramic products for various purposes (artistic, technical, refractory, facing bricks, etc.), makes it possible to develop industrial production. production technologies for products that are in demand in the region and the countries of the Asia-Pacific region. The obtained materials can be used to obtain high-quality import-substituting and export-oriented products using scientifically grounded technologies using clay mass based on local raw materials for the manufacture of products that are in demand by the innovative economy of the region and the country.

Keywords: ceramic materials, composite, hardness, sintering, polymer, modification, nitrides.

New materials and technology

Golovkin P. A. About of hydrogen britteness in the alloy „NMMts 38-2V”

In the process of manufacturing electric vacuum microwave devices for various purposes, a large number of special alloys are used, to which a variety of requirements are imposed, among which one of the main ones is high vacuum density. On the example of the analysis of rods and tapes from a nickel-copper alloy of vacuum melting of the Monel type NMMts 38-2V, the danger of the occurrence in their material of the phenomenon of hydrogen brittleness (hydrogen disease), which is completely unacceptable for parts of electrovacuum devices, is shown. The reasons for the occurrence of hydrogen sickness, features of manifestation, and methods of its timely detection are considered. Based on the results of the research carried out, it is proposed to control semi-finished products from the NMMts 38-2V alloy for the absence of hydrogen embrittlement, as it is carried out according to the standard method for oxygen-free copper.

Keywords: microwave devices, monel alloy, tape, vacuum density, hydrogen embrittlement, chemical composition, copper, impurities, oxygen, structure, grain boundaries, metallography, bend tests.

Belyaev S. N., Novikov V. I. Technological aspects of the forming functional thin-film coatings process on the nodes of precision devices

The paper considers the technological aspects of the thin-film coatings formation on the nodes of precision devices, for example, on the nodes of electrostatic gravitational gradiometer sensitive element suspension. A mathematical description of the sputtering process is presented. The analysis of possible topochemical interactions in the coating deposition zone has been carried out. The technology of layering multilayer coatings has been developed. The features of sputtering process on the surfaces of nodes, which have different shapes, are shown. The equipping means of the sputtering process are presented. The characteristics of coatings (thickness, thickness variation, electrical resistance, roughness, adhesion) have been researched.

Keywords: gravity gradiometer, electrostatic suspension, sputtering, quartz glass, titanium, copper.

Bazhanov D. S., Bogdanova S. F., Borisova N. A., Bulavin D. V., Golubev V. A., Zaytsev A. A., Kiushkin D. V., Kukushkin A. N., Makhov K. O., Nechajkin R. V., Khaldeev V. N. The control program preparing system for digital equipment

The object of this work is the software module „CNC program development system“, which is an integral part of the software complex in the protected design „Complete product life cycle system „Digital enterprise“. The software module is designed to automate the process of developing control programs for process equipment with numerical control. The report contains a description of the development process, the architecture of the software module, requirements for functionality, design solutions, and examples of practical use.

Keywords: product lifecycle management, computer-aided manufacturing, numerical control program, digital enterprise, computer numerical control.

Quality control and measurement technology

Nikitin A. V., Vasilkov D. V., Alexandrov A. S., Golikova V. V. Determination of the deforming ability of technological residual stresses in a thin surface layer of the product based on the method of instrumental identification

There is a problem of obtaining a diagram of technological residual stresses in a thin surface layer of products. This is due to the fact that modern methods of non-destructive testing do not allow one to study subsurface layers with a depth of a few micrometers. This seriously complicates the determination of surface residual stresses. To solve this problem, a method of instrumental identification is proposed to determine the deforming capacity of technological residual stresses. Instrumental identification is implemented directly under load with the construction of an identification diagram. According to the diagram, average stresses are determined, according to which, using test samples, the deforming capacity of technological residual stresses is obtained. To confirm the efficiency of the technique, experimental studies were carried out. They showed that the measurements performed in the microrange made it possible to implement four measurement steps in a layer up to 4,7 μm deep with the possibility of refining the results by the depth of identification. The parameterization of the results using the deforming capacity of technological residual stresses made it possible to determine the surface residual stresses, as well as to evaluate the nature of the stress state of the surface layer of products by comparing the tensile and compression stresses.

Keywords: instrumental identification, surface layer, object of control, average stresses, initial diagram, deforming capacity of technological residual stresses.