Metalloobrabotka № 1 (127)/2022

Metal cutting

Repin D. S., Naumov A. G., Bubnov V. B., Zarubina E. V. The metal cutting application aspects of materials which contain polymers and activated by corona discharge The article presents the results of studies on the emergence of chemical active elements in lubricating and cooling technological means and their influence on the intensity of the course of radical chain reactions in the contact zone during blade cutting of metals. As an example, the effect of a corona discharge on polymer additives with a high oxygen content is considered. A model of the process of activating the course of these reactions when oxygen-containing polymer additives are used as components of lubricating and cooling technological means is presented.

Keywords: theory of the radical chain mechanism, lubricating and cooling technological means,

corona discharge, oxygenated polymer additives, cutting tool.

Kulikov M. Yu., Shevchuk E. O., Larionov M. A., Gusev D. V., Alexandrov I. A. Improving the quality of the surfaces of parts made of polymer-composite materials using SOTC

Effective methods of feeding SOTC (lubricating and cooling technological means) into the cutting zone to improve the surface quality of parts made of polymer-composite materials have been established. The novelty of the work: the efficiency of the supply of SOTC to the cutting zone by spraying was determined, the optimal ratio of air and SOTC was established, which ensures low roughness of the treated surface, and prevents moisture absorption of the material.

Keywords: additive technologies, polymer-composite materials, abrasive treatment, quality,

roughness.

Almawash A. D. Simulation of the metal layers removing for a shaft of variable compliance along the length of the machined surface during circular grinding taking into account the process dynamics on cnc machines

Recently, a continuous improvement in the quality of manufactured machines while ensuring high

productivity of technological processes of their manufacture is one of the main tasks of modern

mechanical engineering. This article presents a mathematical model for calculating the metal removal of a shaft of variable compliance along the length of the machined surface in the process of circular external plunge grinding of a given cycle, taking into account the dynamics of the process on CNC machines. The performance of the model allows you to calculate the values of the actual feed for various sections along the length of the machined surface, in addition to the actual allowance that has already been removed from these sections at the steps of the cycle. The model depends mainly on the cutting force, elastic deformations of the technological system and the operating parameters of the cycle, as well as on the dynamic features.

Keywords: variable compliance, circular grinding, dynamics, machined surface, section.

New materials and technology

Sokolov Yu. A. Designing of argon-arc welding’s industrial system in controllable atmosphere. .

The questions of designing of argon-arc welding’s industrial system in controllable atmosphere are considered in this article. The stratified representation allows to open features of industrial system from the various

points of view. The resulted hierarchical abstraction consists from technological, tool, measuring, information, algorithmic, system striations.

Keywords: designing, hierarchical system, argon-arc welding in controllable atmosphere, process quality, control, mathematical model, algorithms, striations.

Golovkin P. A. Improvementing the quality of amg-group mikroborods by controlling the quantitative containment of intermetallic connections in their material

The paper considers the causes of material vacuum density disturbance and destruction of the coating applied to the surface of aluminum-magnesium alloy microcapsules. It is shown that the destruction of the base material and the applied coating is often associated with a high content and a string arrangement of intermetallic phases which are typical of the alloys of the AMg group. As a material quality parameter it is proposed to use a numerical criterion — quantitative content of intermetallic phases (QCOIP), the use of forging operations is proposed as a tool to control the introduced criterion.

Keywords: microassemblies, aluminium alloy, material, intermetallic phases, slab, bar, forging,

vacuum density.

Arslan H., Korotkih M. T. The use of electromechanical clamping devices by using shape memory materials in machine tools  

The article is devoted to the rationale for the use of automated clamping elements in machine tools

using shape memory alloys. It is shown that such clamping elements can be very compact, easily

automated, and their scope is very wide.

Keywords: clamping elements, shape memory alloys, machine tools.

Design of technological systems

Alexandrov A. S., Vasilkov D. V., Golikova V. V., Starovoitov I. Development of a dynamic model of a technological system for mechanical processing of low-rigid thin-walled workpieces based on modal analysis

In order to develop the configuration of a dynamic model of a technological sys-tem during machining of low-rigid thin-walled parts, a modal analysis was performed. He made it possible to obtain six shapes and corresponding frequencies of natural vibra-tions of the part. The analysis of the results of modal analysis allowed us to form the structure of a dynamic model of a technological system - bending, flat, with two or-thogonal generalized coordinates. A mathematical description of the dynamic model in the space of state variables with the representation of cutting forces in the form of dy-namic characteristics, taking into account their delay in relation to the thickness of the cut, is performed. The conditions of stability of a dynamical system of the sixth order are considered on the basis of the algebraic Hurwitz criterion, according to which the major minors of the Hurwitz determinant must be positive. Theoretical and experimental studies have revealed that violation of the conditions of stability of the cutting process leads to the appearance of intensive fluctuations of the elements of the elastic system, increased wear of the cutting tool, deterioration of the quality of the surface layer of the workpiece and the accuracy of the work, which, in turn, reduces the capabilities of the equipment.

Keywords: low-rigid thin-walled part, technological system, mechanical pro-cessing, modal

analysis, dynamic model, stability, algebraic Hurwitz criterion, stability boundary.