No 2 (140) (2023)
Materials science in mechanical engineering
OBTAINING SIALON FROM SILICON-CONTAINING RAW MATERIALS IN THE MODE OF SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS USING SODIUM AZIDE AND ALUMINUM HALOGENIDES
Abstract
The possibility of obtaining sialon in the SHS-Az mode (self-propagating high-temperature synthesis using sodium azide) from the systems "silicon dioxide – sodium azide – aluminum halogenide – silicon" is viewed. The phase composition and combustion products are analyzed and the average particle size is determined. It was found that particles of a combustion product were combined into agglomerates. The average size of plate-like particles was 300...350 nm, and equiaxed particles – 120...170 nm.
3-7
Technologies of mechanical processing of workpieces
VALUE ELASTICITY ESTIMATION IN PENDULUM SURFACE PLASTIC DEFORMATION
Abstract
The elasticity of the hardened layer under pendulum surface plastic deformation is determined. Calculations are given using computer modeling Ansys 19.1 to estimate the influence of the main technological parameters and modes of pendulum SPD (Surface plastic deformation) by the amount of metal rate of upward gradient, which makes it possible to establish the actual amount of tension and ensure the accuracy of the diametrical dimensions of the hardened parts. The dependence of the elastic rise of the hardened layer on the physical and mechanical properties of the material is given.
8-14
Science intensive technologies of nonmetallic parts production
COMPARATIVE QUALITY ANALYSIS FOR TREATED SURFACE IN ABRUPT AND TRADITIONAL GRINDING OF POLYMER COMPOSITE MATERIALS BASED ON CARBON FIBER
Abstract
Based on the conducted experimental studies regarding the comparative quality analysis for treated surfaces in abrupt and traditional grinding of polymer composite materials, the abrupt grinding performance criteria were determined and an advice list for abrasive processing of PCM was also made
15-25
MODELING OF TECHNOLOGICAL PARAMETERS IN THE MILLING PROCESS OF POLYCARBONATE WORKPIECES UNDER VARIOUS PROCESSING MODES
Abstract
Computer simulation of technological parameters in the milling process of polycarbonate workpieces under various processing modes is realized. The parameters are recorded at various points in the contact time of the milling cutter tooth with the workpiece. The regularities of changes in the parameters of the milling process, including forces and temperatures in the contact zones of the facing with the cutter tooth or in case of tooth contact with the workpiece, depending on the elements of the milling mode, are found. It’s also found that the temperatures in the contact zone of the tooth with the workpiece are higher than in the contact zone of the tooth with the facing. The pattern of temperature distribution in the surface layer of the workpiece is distilled. Mathematical dependences describing the relationship of temperatures with the elements of the milling mode, are obtained
26-31
Surface layer quality, contact interaction, friction and wear of machine parts
GENERALIZED LAW OF CONTACT GLIDING FRICTION OF SOLIDS
Abstract
A mathematical model describing the law of contact gliding friction, taking into account changes in the sliding contact states, is proposed for consideration. The generalization of classical linear models of contact friction is carried out by putting in more additive components allowing for new state transitions of frictional interaction. The developed mathematical model makes it possible to give analytic description of the schematic diagram of classical slip coefficient change depending on the load of B.I. Kostetsky and allows adding to
32-39
Science intensive technologies in coating, parts repair and recovery
TECHNOLOGICAL METHODS FOR DURABILITY EXTENDING OF CYLINDRICAL FRICTION SURFACES
Abstract
Technological methods of worn cylindrical friction surfaces restoration, applicable both in parts production for the elimination of defects, and in machine maintenance for worn friction surfaces restoration, are viewed
40-48