The Experts below are selected from a list of 21363 Experts worldwide ranked by ideXlab platform
D.a. Ivanov - One of the best experts on this subject based on the ideXlab platform.
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A novel operando approach to analyze the structural evolution of metallic materials during Friction with application of synchrotron radiation
2020Co-Authors: I.a. Bataev, D.v. Lazurenko, A.a. Bataev, V.g. Burov, I.v. Ivanov, K.i. Emurlaev, A.i. Smirnov, M. Rosenthal, M. Burghammer, D.a. IvanovAbstract:In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and Friction. The setup is particularly suited for testing various Friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems related to significant scattering of X-rays produced by metals and makes it possible using “real samples” in synchrotron beamlines operating in reflection mode. To demonstrate the capabilities of the device and the proposed new approach, an iron-based massive sample was subjected to thousands of Friction cycles using a cemented carbide pin. The material was probed with synchrotron X-ray radiation within a few milliseconds after leaving the Friction Zone. The results of the microstructural and structural analysis, as well as results obtained from diverse mathematical models, allowed us to evaluate several features, including gradual accumulation of defects, microstructural refinement, dislocation density changes, surface layer oxidation, as well as several other phenomena caused by the dry sliding Friction process. Mainly, it was possible to conclude that the process of wear occurred due to the cooperative action of oxidation and plastic deformation, which began during the first cycle of Frictional interaction and was manifested in increasing the dislocation density, whose type was changed gradually during testing. The number of defects quickly reached a threshold value and subsequently fluctuated around it due to periodically repeated processes of defect accumulation and stress relaxation resulting from material wear. It was also observed that Friction led to the quick formation of a mechanically mixed layer, consisting of the sample material and a mixture of two types of iron oxide – hematite and magnetite. The delamination of this layer was probably the primary wear mechanism.
I.a. Bataev - One of the best experts on this subject based on the ideXlab platform.
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A novel operando approach to analyze the structural evolution of metallic materials during Friction with application of synchrotron radiation
2020Co-Authors: I.a. Bataev, D.v. Lazurenko, A.a. Bataev, V.g. Burov, I.v. Ivanov, K.i. Emurlaev, A.i. Smirnov, M. Rosenthal, M. Burghammer, D.a. IvanovAbstract:In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and Friction. The setup is particularly suited for testing various Friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems related to significant scattering of X-rays produced by metals and makes it possible using “real samples” in synchrotron beamlines operating in reflection mode. To demonstrate the capabilities of the device and the proposed new approach, an iron-based massive sample was subjected to thousands of Friction cycles using a cemented carbide pin. The material was probed with synchrotron X-ray radiation within a few milliseconds after leaving the Friction Zone. The results of the microstructural and structural analysis, as well as results obtained from diverse mathematical models, allowed us to evaluate several features, including gradual accumulation of defects, microstructural refinement, dislocation density changes, surface layer oxidation, as well as several other phenomena caused by the dry sliding Friction process. Mainly, it was possible to conclude that the process of wear occurred due to the cooperative action of oxidation and plastic deformation, which began during the first cycle of Frictional interaction and was manifested in increasing the dislocation density, whose type was changed gradually during testing. The number of defects quickly reached a threshold value and subsequently fluctuated around it due to periodically repeated processes of defect accumulation and stress relaxation resulting from material wear. It was also observed that Friction led to the quick formation of a mechanically mixed layer, consisting of the sample material and a mixture of two types of iron oxide – hematite and magnetite. The delamination of this layer was probably the primary wear mechanism.
V V Fadin - One of the best experts on this subject based on the ideXlab platform.
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about wear and average surface temperature of copper or steel contacts at sliding current collection
2015Co-Authors: V V Fadin, M I Aleutdinova, Ye V RubtsovAbstract:Wear intensity and the average surface temperature of contact between copper and 1020 steel in dry sliding with a contact density higher 100 A/cm2 are defined. It is shown that the temperature decreases linearly along the specimen with an increasing of distance from a contact surface. It is established that copper forms a Friction Zone with lower average contact surface temperature and with lower wear intensity in comparison with those of 1020 steel. It is caused by the lower local shear stability of copper comparing with that of 1020 steel. The explanation of this fact is offered on the basis of idea of low copper shear stability (i.e. copper high plasticity) that leads to easy relaxation of mechanical stresses in the field of stress concentrators. In this case, the surface layer is deformed locally at the low structural level and the low speed of structural defects formation is manifested. Rather high fatigue resistance of a surface layer takes place as a result. These factors and high heat conductivity...
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morphological features of the copper surface layer under sliding with high density electric current
2015Co-Authors: V V Fadin, M I Aleutdinova, Ye V Rubtsov, Valeriya A AleutdinovaAbstract:Conductivity and wear intensity of copper under the influence of dry Friction and electric current with contact density higher 100 A/cm2 are presented. It is shown that an increase in hardness and heat outflow from a Friction Zone leads to the reduction of wear intensity and current contact density increase corresponding to the beginning of catastrophic wear. Structural changes, such as the formation of FeO oxide and α-Fe particles in the copper surface layer, have also been found. It is observed that a worn surface is deformed according to a viscous liquid mechanism. Such singularity is explained in terms of appearance of high-excited atomic states in deforming micro-volumes near contact spots that lead to easy stress relaxation by local plastic shears in the vicinity of stress concentrators. In common this effect allows to achieve high wear resistance.
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effect of the phase composition of steel based composites on the electrical resistance of the Friction Zone under conditions of current collection
2009Co-Authors: V V Fadin, M I AleutdinovaAbstract:The current-voltage diagram of the electric contact Zone and the wear rate of sintered composites based on ball-bearing wastes steel (1.5% Cr) and Hadfield steel (13% Mn) at sliding over quenched steel (0.45% C) are investigated with tin and lead incorporated in the Friction Zone. It is established that melting is accompanied by a significant decrease in the electrical resistance which causes the nonlinearity of the current-voltage diagram of the contact. An increase in the strength of the contact layers manifested through the increased wear resistance is simultaneously observed. Based on the Ohm law, it is qualitatively demonstrated that the nonlinearity is caused by the change of the true area of electrical contact. Results of analogous experiments for composites that do not contain lead or tin are presented. It is established that the electrical conductivity and the strength of the surface layer sharply decrease for such change of the phase composition.
M I Aleutdinova - One of the best experts on this subject based on the ideXlab platform.
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about wear and average surface temperature of copper or steel contacts at sliding current collection
2015Co-Authors: V V Fadin, M I Aleutdinova, Ye V RubtsovAbstract:Wear intensity and the average surface temperature of contact between copper and 1020 steel in dry sliding with a contact density higher 100 A/cm2 are defined. It is shown that the temperature decreases linearly along the specimen with an increasing of distance from a contact surface. It is established that copper forms a Friction Zone with lower average contact surface temperature and with lower wear intensity in comparison with those of 1020 steel. It is caused by the lower local shear stability of copper comparing with that of 1020 steel. The explanation of this fact is offered on the basis of idea of low copper shear stability (i.e. copper high plasticity) that leads to easy relaxation of mechanical stresses in the field of stress concentrators. In this case, the surface layer is deformed locally at the low structural level and the low speed of structural defects formation is manifested. Rather high fatigue resistance of a surface layer takes place as a result. These factors and high heat conductivity...
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morphological features of the copper surface layer under sliding with high density electric current
2015Co-Authors: V V Fadin, M I Aleutdinova, Ye V Rubtsov, Valeriya A AleutdinovaAbstract:Conductivity and wear intensity of copper under the influence of dry Friction and electric current with contact density higher 100 A/cm2 are presented. It is shown that an increase in hardness and heat outflow from a Friction Zone leads to the reduction of wear intensity and current contact density increase corresponding to the beginning of catastrophic wear. Structural changes, such as the formation of FeO oxide and α-Fe particles in the copper surface layer, have also been found. It is observed that a worn surface is deformed according to a viscous liquid mechanism. Such singularity is explained in terms of appearance of high-excited atomic states in deforming micro-volumes near contact spots that lead to easy stress relaxation by local plastic shears in the vicinity of stress concentrators. In common this effect allows to achieve high wear resistance.
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effect of the phase composition of steel based composites on the electrical resistance of the Friction Zone under conditions of current collection
2009Co-Authors: V V Fadin, M I AleutdinovaAbstract:The current-voltage diagram of the electric contact Zone and the wear rate of sintered composites based on ball-bearing wastes steel (1.5% Cr) and Hadfield steel (13% Mn) at sliding over quenched steel (0.45% C) are investigated with tin and lead incorporated in the Friction Zone. It is established that melting is accompanied by a significant decrease in the electrical resistance which causes the nonlinearity of the current-voltage diagram of the contact. An increase in the strength of the contact layers manifested through the increased wear resistance is simultaneously observed. Based on the Ohm law, it is qualitatively demonstrated that the nonlinearity is caused by the change of the true area of electrical contact. Results of analogous experiments for composites that do not contain lead or tin are presented. It is established that the electrical conductivity and the strength of the surface layer sharply decrease for such change of the phase composition.
V.g. Burov - One of the best experts on this subject based on the ideXlab platform.
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A novel operando approach to analyze the structural evolution of metallic materials during Friction with application of synchrotron radiation
2020Co-Authors: I.a. Bataev, D.v. Lazurenko, A.a. Bataev, V.g. Burov, I.v. Ivanov, K.i. Emurlaev, A.i. Smirnov, M. Rosenthal, M. Burghammer, D.a. IvanovAbstract:In this study, we describe an experimental setup and a new approach for operando investigation of structural evolution of materials during wear and Friction. The setup is particularly suited for testing various Friction pairs, including those in which both rubbing bodies are made of metals. The developed device allows circumventing the problems related to significant scattering of X-rays produced by metals and makes it possible using “real samples” in synchrotron beamlines operating in reflection mode. To demonstrate the capabilities of the device and the proposed new approach, an iron-based massive sample was subjected to thousands of Friction cycles using a cemented carbide pin. The material was probed with synchrotron X-ray radiation within a few milliseconds after leaving the Friction Zone. The results of the microstructural and structural analysis, as well as results obtained from diverse mathematical models, allowed us to evaluate several features, including gradual accumulation of defects, microstructural refinement, dislocation density changes, surface layer oxidation, as well as several other phenomena caused by the dry sliding Friction process. Mainly, it was possible to conclude that the process of wear occurred due to the cooperative action of oxidation and plastic deformation, which began during the first cycle of Frictional interaction and was manifested in increasing the dislocation density, whose type was changed gradually during testing. The number of defects quickly reached a threshold value and subsequently fluctuated around it due to periodically repeated processes of defect accumulation and stress relaxation resulting from material wear. It was also observed that Friction led to the quick formation of a mechanically mixed layer, consisting of the sample material and a mixture of two types of iron oxide – hematite and magnetite. The delamination of this layer was probably the primary wear mechanism.
