Modelling the Temperature Field of a Surface in Using Electrospark Alloying of Metals

Introduction. To keep automobiles and tractors in operation conditions, it is necessary to restore the inner cylindrical surfaces of the friction pair parts. This is the most laborintensive activity. The method of electroplated contact deposition of composite coatings, based on elastic plastic deformation of formed layers, is used for repairing surfaces. To use this method it is necessary to determine the values of the elasticity modulus, on which the wear resistance of tribocouplings depends. Materials and Methods. For the study, cylindrical samples made of 30 HGSA and 30 HGSNA steels were used. Electrolyte containing 200–250 g/l chromium oxide, 2.0–2.5 g/l sulfuric acid, and distilled water was used for electroplating the coatings. When calculating the stress-strain state, the apparatus of continuum mechanics was used. Results. The dependence of the coating pliability as a function of the parameters of individual elementary layers is determined. When the multilayer coating of three types (orthogonal-reinforced, cross-reinforced and quasi-isotropic) is applied, its structure does not depend on the angles of kinematic tool movement on the inner cylindrical surface of the part. For each type of coatings, the way to determine the constant stiffness coefficients of the layers is specified. The dependences for calculating the elasticity modulus of the applied material are derived from the values of the stiffness coefficients. Discussion and Conclusion. In determining the modulus of elasticity of multilayered composite coatings, the calculation is made for the individual layers by passing to the convective coordinates, which is in complete agreement with the Lagrange point of view on the study of the motion of a continuous medium. The results obtained are of practical significance in the selection of the coating material to be applied for the restoration of internal cylindrical surfaces.

Section: материалы и методыunclassified

Estimation of the Elasticity Modulus of Composite Electroplated Coatings during Their Layer-by-Layer Deposition

Zhachkin

Zavrazhnov

Penkov

et al. 2021

Effect of Chromium Addition and Regimes during Electrospark Alloying with Aluminum Matrix Anode Material of Steel 45

Николенко

Konevtsov

Гордиенко

et al. 2021

Self Cite

Introduction. Electrospark alloying is used to produce hardening coatings. Anodic materials with unique properties include metal matrix composites based on aluminum. The aim of the work is to develop new aluminum matrix anode composite materials with high efficiency indicators during electrospark alloying of carbon steel 45. Materials and Methods. Structural carbon steel 45 was used as the substrate (cathode). Aluminum matrix materials are chosen as the anode materials. The value of the cathode weight increment and the anode erosion were determined by the gravimetric method on the Shinko Denshi HTR-220 CE electronic scale with an accuracy of ±∙10–4 g. To study the microstructure and metallography of the surface of the anode materials, the microscopes EVO-50 XVP and Altami MET 3 APO from S. ZEISS were used. The device CALOTEST CSM Instruments was used to study coatings for microabrasive wear. Results. There is developed a methodological scheme for achieving the efficiency of the electric spark alloying parameters and the properties of the doped layer depending on the composition of the anodic metal matrix composite material based on aluminum with the addition of chromium and processing modes. The mode of Institute of Materials Science electrospark installation with pulse energy of 14.4 J was set for anode material application during electrospark alloying. It is established that after electric spark alloying of steel 45, the hardness and wear resistance of the surface increase by 2-3 times, and the heat resistance ‒ by 5–18 times. Discussion and Conclusion. The series of increasing the cathode mass, the erosion resistance of the electrode materials, mass transfer coefficient, heat resistance, hardness and wear resistance of the alloyed layer are obtained. The obtained series are a convenient tool for achieving various efficiency parameters in electric spark alloying depending on the selected anode material and processing modes.

Assessment of Tribotechnical Properties of Consolidated Materials Obtained by Electrospark Processing

Величко

Martynov

Martynova

2023

Introduction. The bakery industry is an agricultural industry of high-level processing of raw materials focuses on the end-consumer. In the production of bakery products one of the operations of the technological process is performed by dough dividers of vacuumpiston type, whose service life is 30‒40% lower than the normative. The most promising method for restoration of worn parts of the suction mechanism is electrospark processing. When selecting the electrode material, it is important that they have not only low erosion resistance, but also high tribotechnical properties. Aim of the Article. The article deals with problem of selecting electric coatings to reduce wear of working surfaces of suction mechanism parts during repair of vacuum piston-type dough dividers. Materials and Methods. The analysis of the properties of electropark coatings was carried out by nondestructive testing methods using modern research equipment; the results were processed using the Compass-3D program. Results. There are determined the values of physical, mechanical, frictional and tribotechnical properties of electrospark coatings made of BrOS10-10 bronze and Kh15N60 alloy. The total wear rate for BrOS10-10 bronze coating was 8,3 ∙ 10‒12, and for Kh15N60 alloy 15 ∙ 10‒12. Discussion and Conclusion. Total wear rate on the friction machine of bronze coated samples is lower than that of basic friction pair in 1.4 times, and of alloy coated samples ‒ higher in 1.26 times. Adding of MODENGY solid-lubricant coating to the coating from the alloy reduces its abrasion ability by 3 times, and the total wear rate ‒ by 1.34 times in comparison with the base friction pair. The used calculation-experimental method showed low wear rate of electrospark coatings of bronze and alloy in relation to the material of parts of the suction mechanism of vacuum-piston-type dough dividing machines.