scholarly journals Electromechanical Surfacing Technique

2022 ◽  
Author(s):  
A. Gerasimova
Keyword(s):  
Surface Layer ◽  
Phase Change ◽  
Original Structure ◽  
Electromechanical Treatment ◽  
Temperature Rate

Abstract. The paper considers an electromechanical surfacing technique of parts’ work surfaces. It was found out that depending on strain temperature, rate and degree there were special type structures formed on a surface layer with a phase change (a bright layer), i.e. a hot deformed structure with and without recrystallization and a cold deformed structure. Depending on the original structure and hardening conditions, during surfacing of parts a thickness of this area may achieve 0.3 mm max. Impact of steel electromechanical treatment on the structure and the surface layer was found out. Depending on properties of surfaces being treated it is possible to use plate-like and roller-type tools for electromechanical hardening. It was shown that roller- type tools possessed enhanced durability and enlarged areas of surfaces being treated, though ensured poorer finish of surfaces being treated.

Infiltration into columns of swelling soil as studied by high speed photography

Soil Research ◽  
1970 ◽  
Vol 8 (2) ◽  
pp. 195 ◽  
Author(s):  
N Collis-George ◽  
R Lal
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Motion Pictures ◽  
Original Structure ◽  
High Speed Photography ◽  
Surface Layers ◽  
Depth Zone ◽  
Swelling Soil

Columns of aggregates of a soil, which slakes into microaggregates of about 30 � diameter as well as swelling on quick wetting, were examined by high speed photography during infiltration. Because of the collapse of the original structure of surface layers, the supply of water to deeper layers is restricted. Examination of motion pictures and magnified stills for the depth zone just below the collapsed surface layer provides a description of the phenomena occurring during the advance of the front. These phenomena are discussed in terms of limitations of the procedure used, the mechanism of wetting, the displacement of particles, infiltration behaviour, and the nature of swelling and slaking in these systems.

Study of medium-carbon steels structure after electromechanical processing

2020 ◽  
pp. 473-477
Author(s):  
Yu.S. Ivanova ◽  
V.N. Zaripov ◽  
Ngo Van Tuyen ◽  
Myat Soe Lwin ◽  
Ye Kyaw Oo
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Heat Stability ◽  
Carbon Steels ◽  
Original Structure ◽  
Surface Microhardness ◽  
Medium Carbon ◽  
Wide Range ◽  
Medium Carbon Steels ◽  
40Cr Steel

The results of the microstructure and microhardness of the surface layer of medium-carbon 40Cr, 38CrNi3MoA steels after electromechanical processing are presented. The results of tests on the heat stability of samples made of 38CrNi3MoA steel when they are consistently heated from 150 to 550 °C, in the temperature range of 50 °C are presented. The samples are heated in muffle furnaces with exposure at each temperature of 10 min and cooled in air. The heat stability of the surface layer after electromechanical processing is controlled by changes in microhardness. The results of the microstructure indicate the formation of fine martensite and retained austenite in the upper layers of the quenching zones. High speed heating of local volume of the surface with parallel thermoplastic shaping by work-hardening tool and following high-intensity cooling through heat rejection in deep into work material take place in the time of electromechanical processing. The structure of sorbite is form in the overlap zone of electro-mechanical hardening and in the transition near original structure section. The average surface microhardness of the 40Cr steel samples before hardening is HV = 2000...2400 MPa, after electromechanical hardening — HV = 6640 MPa, and the 38CrNi3MoA steel samples before hardening is HV = 2000...2200 MPa, after electromechanical hardening — HV = 7060 MPa. The graded layer has hardening depth to 0.8 mm with stepwise degradation of hardness is detected. The research results show that using electromechanical processing in the manufacture of wide range of parts in order to increase the wear resistance of the surface layer.

Structure and Properties of Surface Alloys in Ti-Y System

2014 ◽  
Vol 1013 ◽  
pp. 229-233 ◽  
Author(s):  
Yurii F. Ivanov ◽  
Anton D. Teresov ◽  
Olga Ivanova ◽  
Victor Gromov ◽  
Sergei Raikov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Friction Coefficient ◽  
Coefficient Of Friction ◽  
Original Structure ◽  
Structure And Properties ◽  
Multiphase Structure ◽  
High Microhardness ◽  
Intense Electron Beam ◽  
Intense Electron

The doping of the surface layer of titanium by the yttrium, oxygen and carbon was implemented. Irradiation of the doped layer by intense electron beam leads to the formation of the multiphase structure and the nanosubmicron range having a high microhardness (at 3-fold higher than the hardness of the original structure) and a low coefficient of friction (6 times lower than the friction coefficient of the starting material).

scholarly journals Surface layer of 40Kh steel after electromechanical treatment with dynamic force impact

2021 ◽  
Vol 64 (4) ◽  
pp. 259-265
Author(s):  
N. G. Dudkina ◽  
V. N. Arisova
Keyword(s):  
Surface Layer ◽  
Steel Surface ◽  
White Layer ◽  
Amorphous State ◽  
Hardened Layer ◽  
Simultaneous Increase ◽  
Dynamic Force ◽  
40Kh Steel ◽  
Electromechanical Treatment ◽  
Force Impact

The paper presents the results of complex studies of the structure, microhardness and depth of the hardened surface layer of 40Kh steel formed as a result of electromechanical treatment with dynamic application of a deforming force (EMT with impact). The research was carried out using optical microscopy, X-ray diffraction analysis, and microhardness methods. The method of electromechanical treatment with dynamic force impact consisted in simultaneous transmission of electric current pulses and deforming force through the contact zone of the tool with the part. As a result of shock-thermal effects with different current densities (j = 100 A/mm2; 300 A/mm2; 600 A/mm2), segments of the hardened layer of different sizes and structure composition are formed on the steel surface in cross-section. Analysis of structural and phase transformations in the surface layer of 40Kh steel subjected to dynamic electromechanical treatment indicates the formation of a specific structure of the white layer, the structure and properties close to the amorphous state of the metal with a maximum hardness HV = 8.0 – 8.5 GPa. As you move away from the surface, a transition zone is formed behind the segment of the white layer with a structure that does not have the characteristic needle structure of martensite. It was found that with an increase in the current density during shock electromechanical treatment, the depth of hardening increases by 4 – 5 times with a simultaneous increase in the heterogeneity of strength properties; the level of micro-stresses increases by 25 %. Experimental data on the structural state, microhardness and depth of the surface layer of 40Kh steel show that electromechanical treatment with dynamic (shock) application of the deforming force causes deeper transformations in the steel structure compared to traditional static EMT. The results obtained show that as a result of electro-mechanical processing with impact, the intensity of the temperature-force effect on the steel surface layer increases, which allows you to open the internal reserves of 40Kh steel and control the process of forming its structure and phase states.

scholarly journals Influence of reinforcing plastic surface deformation on surface performance of machine parts

2019 ◽  
pp. 7-14
Author(s):  
Z. М. Оdosii ◽  
V. Ya. Shymanskyi ◽  
B. V. Pindra
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Residual Stresses ◽  
Surface Deformation ◽  
Fatigue Cracks ◽  
Surface Plastic Deformation ◽  
Original Structure ◽  
Physical Parameters ◽  
Surface Plastic ◽  
Machine Parts

The performance of the machines part reinforcement using surface plastic deformation shall be considered as formation of the whole complex of surface parameters and quality and their impact on the operational properties of these parts. The main surface quality parameters, affecting the performance of machine parts are geometric (microgeometry, wavelength, roughness, shape of inequalities, the size of the supporting surface, the direction of the traces of processing); physical parameters (structure, degree and slander depth, residual stresses in the surface layer). In the machine building, many methods of superficial plastic deformation are used for part reinforcement; these methods essentially differ in the scheme of impact of the surface deforming part to be treated. After analyzing the results obtained by scientists, involved in research on surface plastic deformation of surface layers and surfaces of parts, it was found that after hardening, practically all structural changes contribute to reinforcement of the surface layer material and increase the plastic deformation resistance. Increasing the density of dislocations and the separation of carbides, which block the shear slides and create obstacles to the movement of dislocations. Due to these changes, resistance to formation and spread of fatigue cracks have increased. The treatment depth, magnitude of residual stresses and increase in hardness depends on the original structure and chemical composition of the material. Reinforcement regimes have significant effects on the wear resistance. Use  of diamond smoothing, vibration processing, combined methods (surface plastic deformation in combination with other reinforcement methods, as well as the use of a combined tool) opens up new possibilities for increasing the quality characteristics of the surface and the surface layer of parts, and accordingly, increasing their operational properties with all the diversity and complexity of used processes. Based on the results of the studies, practical recommendations on the application of methods of hardening by surface plastic deformation of machine parts and a methodology for designing technological processes for their manufacture considering manufacturing capabilities are proposed.

scholarly journals Calculation of temperature fields during finishing and strengthening electromechanical treatment of bodies of rotation moving along a helical line by a high-temperature source

2020 ◽  
Vol 329 ◽  
pp. 03057
Author(s):  
Alexander Morozov ◽  
Lilia Khabieva ◽  
Alexey Knyurov ◽  
Sergey Petryakov ◽  
Julia Nuretdinova
Keyword(s):  
Surface Layer ◽  
High Temperature ◽  
Temperature Fields ◽  
Helical Line ◽  
Mechanical Processing ◽  
Electromechanical Treatment ◽  
Processing Modes

The obtained approximate analytical dependences on the calculation of temperature fields in the processed part during finishing and strengthening electro-mechanical processing allow us to predict the properties of the surface layer and assign processing modes based on the characteristics of operation.

TECHNOLOGY OF COMBINED ELECTROMECHANICAL TREATMENT WITH PROFILE ROLLING

2020 ◽  
pp. 21-27
Author(s):  
V. R. Edigarov
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Surface Layer ◽  
Surface Plastic Deformation ◽  
Surface Plastic ◽  
Electromechanical Treatment ◽  
Lubricating Material ◽  
Increase Wear Resistance ◽  
Oil Pockets ◽  
Selection Of

The technology of combined electromechanical treatment with profile rolling is presented, which is a combination of electromechanical treatment and surface plastic deformation, which allows to create on the surface directed regular microrelief. The proposed technology is tested during processing of parts of multipurpose tracked and wheeled machines operating under difficult loading conditions, signalternating dynamic loads, often with limited lubricant or presence of abrasive in its composition. Reasonable selection of relief (pattern) of treated surface makes it possible to maximize retention of lubricating material in zone of tribocontact, as well as to increase wear resistance of parts and to create residual compression stresses in surface layer. The mechanical properties of the surface layer of the sample with a strengthened geometric pattern by changing the microhardness of the smoothed surface and oil pockets (channels) obtained by surface plastic deformation were examined. Electromechanical treatment by rolling the profile makes it possible to create on the surface a strengthened surface layer with naturally varying parameters with the specified regular micro-relief including oil pockets (channels) and reinforced tracks, at the same time considerable increase of wear resistance of triboscreating is provided.

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