Pub Date : 2022-12-15DOI: 10.17212/1994-6309-2022-24.4-98-112
V. Zakovorotny, V. Gvindjiliya, E. Fesenko
Introduction. One of the dynamically developing areas of increasing the efficiency of CNC machines is associated with the use of the synergetic concept in determining the CNC program. The principle of compression-expansion of the dimensionality of the state space is used. Subject. On the example of the workpiece machining, the stiffness parameters of which are a function of the toolpath, all stages of control synthesis, which ensures the mutual consistency of dynamic subsystems, including the cutting process, are described in the paper. The aim of the work is to determine asymptotically stable machine actuator toolpath, given by CNC program parameters, from the set of paths, for which the condition of minimum wear intensity is fulfilled. Method and methodology. Mathematical modeling of the controlled cutting system, which is based on the principle of compression-expansion state space, is presented. When the dimension of the state space is expanded, the model of the dynamic cutting system includes all elements from the CNC system that programs the motion of the actuating elements to the elastic deformations of the tool, which interacts with the workpiece through the connection formed by the cutting process. The dynamic coupling integrates the subsystems into a single coupled control system. In this space, the desired shaping motion path of the tool tip relative to the workpiece is constructed, which should be the attractor of the entire state space. The transformation of the desired motion path into an attractor characterizes the procedure of compressing the dimensionality of the state space. It is supposed that it is possible to control the motion trajectories of the actuators within the bandwidths of the servomotors. Results and Discussion. The analysis of the stability of the cutting process is performed; the example of the efficiency of a NC program on the basis of the synergetic paradigm is presented. It is shown that by coordinating the external control with the internal dynamics of the system it is possible to increase the efficiency of a part production up to two times in machine time.
{"title":"Application of the synergistic concept in determining the CNC program for turning","authors":"V. Zakovorotny, V. Gvindjiliya, E. Fesenko","doi":"10.17212/1994-6309-2022-24.4-98-112","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.4-98-112","url":null,"abstract":"Introduction. One of the dynamically developing areas of increasing the efficiency of CNC machines is associated with the use of the synergetic concept in determining the CNC program. The principle of compression-expansion of the dimensionality of the state space is used. Subject. On the example of the workpiece machining, the stiffness parameters of which are a function of the toolpath, all stages of control synthesis, which ensures the mutual consistency of dynamic subsystems, including the cutting process, are described in the paper. The aim of the work is to determine asymptotically stable machine actuator toolpath, given by CNC program parameters, from the set of paths, for which the condition of minimum wear intensity is fulfilled. Method and methodology. Mathematical modeling of the controlled cutting system, which is based on the principle of compression-expansion state space, is presented. When the dimension of the state space is expanded, the model of the dynamic cutting system includes all elements from the CNC system that programs the motion of the actuating elements to the elastic deformations of the tool, which interacts with the workpiece through the connection formed by the cutting process. The dynamic coupling integrates the subsystems into a single coupled control system. In this space, the desired shaping motion path of the tool tip relative to the workpiece is constructed, which should be the attractor of the entire state space. The transformation of the desired motion path into an attractor characterizes the procedure of compressing the dimensionality of the state space. It is supposed that it is possible to control the motion trajectories of the actuators within the bandwidths of the servomotors. Results and Discussion. The analysis of the stability of the cutting process is performed; the example of the efficiency of a NC program on the basis of the synergetic paradigm is presented. It is shown that by coordinating the external control with the internal dynamics of the system it is possible to increase the efficiency of a part production up to two times in machine time.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43024548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-15DOI: 10.17212/1994-6309-2022-24.4-6-17
A. Dyuryagin, D. Ardashev
Introduction. Currently, a substantial proportion of the machine-building industry is made up of one-off products or products manufactured in small batches. In this regard, innovative approaches to obtaining such products are being actively applied in order to reduce the cost of special, expensive tooling of the blanking process. Such technologies include the Direct Metal Deposition (DMD) method, the essence of which is the deposition of metal particles from a gas-powder stream. This method has a lot of advantages, but one of the main drawbacks is that the products after growing have a rough surface and do not meet the accuracy requirements of the finished part drawing. Consequently, the parts require further machining by cutting. However, due to the novelty of the materials, there are no regime parameters for machining. In this regard, the aim of the work is to establish the functional relationship between the cutting force and roughness of the machined surface with the feed per tooth during end milling of EuTroLoy 16604 material formed by DMD-method. In this paper an experimental study of cutting force and roughness of machined surface with varying the tooth feed during end milling is carried out. The research method is an experiment on milling of EuTroLoy 16604 material obtained by DMD-method with measuring the output parameters of the process (cutting force and roughness of the machined surface). Results and discussion. The measured values of cutting force and roughness of the machined surface allowed establishing functional and graphical dependences of the output parameters of the milling process on the feed per tooth. It is found that using a cutter with a smaller clearance angle results in lower cutting forces and the surface has a lower height of microroughness. Thus, the developed functional relationships of cutting force and roughness of the machined surface with the feed per tooth allow predicting the output parameters of the cutting process and increasing the efficiency of machining operations by cutting. A promising direction for further work is seen in the study of relative machinability and evaluation of its quantitative value.
{"title":"A study of the relationship between cutting force and machined surface roughness with the feed per tooth when milling EuTroLoy 16604 material produced by the DMD method","authors":"A. Dyuryagin, D. Ardashev","doi":"10.17212/1994-6309-2022-24.4-6-17","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.4-6-17","url":null,"abstract":"Introduction. Currently, a substantial proportion of the machine-building industry is made up of one-off products or products manufactured in small batches. In this regard, innovative approaches to obtaining such products are being actively applied in order to reduce the cost of special, expensive tooling of the blanking process. Such technologies include the Direct Metal Deposition (DMD) method, the essence of which is the deposition of metal particles from a gas-powder stream. This method has a lot of advantages, but one of the main drawbacks is that the products after growing have a rough surface and do not meet the accuracy requirements of the finished part drawing. Consequently, the parts require further machining by cutting. However, due to the novelty of the materials, there are no regime parameters for machining. In this regard, the aim of the work is to establish the functional relationship between the cutting force and roughness of the machined surface with the feed per tooth during end milling of EuTroLoy 16604 material formed by DMD-method. In this paper an experimental study of cutting force and roughness of machined surface with varying the tooth feed during end milling is carried out. The research method is an experiment on milling of EuTroLoy 16604 material obtained by DMD-method with measuring the output parameters of the process (cutting force and roughness of the machined surface). Results and discussion. The measured values of cutting force and roughness of the machined surface allowed establishing functional and graphical dependences of the output parameters of the milling process on the feed per tooth. It is found that using a cutter with a smaller clearance angle results in lower cutting forces and the surface has a lower height of microroughness. Thus, the developed functional relationships of cutting force and roughness of the machined surface with the feed per tooth allow predicting the output parameters of the cutting process and increasing the efficiency of machining operations by cutting. A promising direction for further work is seen in the study of relative machinability and evaluation of its quantitative value.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48523393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-15DOI: 10.17212/1994-6309-2022-24.4-113-126
R. Sokolov, V. Novikov, Ilja Kovenskij, K. Muratov, Anatoli Z. Venediktov, L. Chaugarova
Introduction. The properties of steels are determined by many factors, including the manufacturing process and subsequent treatment. Some features of these processes lead to the fact that in steel, apart from alloying elements added to obtain a certain level of physical and mechanical properties, there are also foreign impurities that enter it at various stages. Foreign elements can not only dissolve in the matrix, but also participate in the formation of particles of nonmetallic inclusions acting as defects. Its presence significantly affects the performance characteristics of the material. That is why it is necessary to understand the processes that lead to the appearance of nonmetallic inclusions and affect its shape. Purpose: to consider the effect of heat treatment, leading to the appearance of a ferrite-martensitic structure, on the shape and size of nonmetallic inclusions; to determine its influence on the physical and mechanical properties of the material. In the work, samples of rolled steel 09Mn2Si after heat treatment are studied. Research methods. To study the properties and structure of steel 09Mn2Si, the following methods were used: scanning electron microscopy – to study the structure of the material, chemical composition in the local area and the site under study and to determine the accumulation of impurities; SIAMS 800 software and hardware complex – to compare the structure of the material with the atlas of microstructures, to determine the score of the grain structure, differences in the structural and phase composition occurring during heat treatment; portable X-ray fluorescence analyzer of metals and alloys X-MET 7000 - to determine the chemical composition of the samples under study in percentage terms; Vickers hardness tester with a preload of 20 kg – to measure the hardness of the samples under study. Results and discussions. It is found that in the low-alloy low-carbon structural steel 09Mn2Si in most cases there are nonmetallic inclusions of the type of manganese sulfide formed during its manufacture. When this steel is heated to the temperatures of the intercritical transition, this compound is formed in the area of grain boundaries in the form of spherical inclusions. The presence of these inclusions significantly affects the strength and corrosion properties. Manganese sulfide acts as the point of the corrosion process initiation.
{"title":"The effect of heat treatment on the formation of MnS compound in low-carbon structural steel 09Mn2Si","authors":"R. Sokolov, V. Novikov, Ilja Kovenskij, K. Muratov, Anatoli Z. Venediktov, L. Chaugarova","doi":"10.17212/1994-6309-2022-24.4-113-126","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.4-113-126","url":null,"abstract":"Introduction. The properties of steels are determined by many factors, including the manufacturing process and subsequent treatment. Some features of these processes lead to the fact that in steel, apart from alloying elements added to obtain a certain level of physical and mechanical properties, there are also foreign impurities that enter it at various stages. Foreign elements can not only dissolve in the matrix, but also participate in the formation of particles of nonmetallic inclusions acting as defects. Its presence significantly affects the performance characteristics of the material. That is why it is necessary to understand the processes that lead to the appearance of nonmetallic inclusions and affect its shape. Purpose: to consider the effect of heat treatment, leading to the appearance of a ferrite-martensitic structure, on the shape and size of nonmetallic inclusions; to determine its influence on the physical and mechanical properties of the material. In the work, samples of rolled steel 09Mn2Si after heat treatment are studied. Research methods. To study the properties and structure of steel 09Mn2Si, the following methods were used: scanning electron microscopy – to study the structure of the material, chemical composition in the local area and the site under study and to determine the accumulation of impurities; SIAMS 800 software and hardware complex – to compare the structure of the material with the atlas of microstructures, to determine the score of the grain structure, differences in the structural and phase composition occurring during heat treatment; portable X-ray fluorescence analyzer of metals and alloys X-MET 7000 - to determine the chemical composition of the samples under study in percentage terms; Vickers hardness tester with a preload of 20 kg – to measure the hardness of the samples under study. Results and discussions. It is found that in the low-alloy low-carbon structural steel 09Mn2Si in most cases there are nonmetallic inclusions of the type of manganese sulfide formed during its manufacture. When this steel is heated to the temperatures of the intercritical transition, this compound is formed in the area of grain boundaries in the form of spherical inclusions. The presence of these inclusions significantly affects the strength and corrosion properties. Manganese sulfide acts as the point of the corrosion process initiation.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44290642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-15DOI: 10.17212/1994-6309-2022-24.3-6-21
G. Permyakov, R. Davlyatshin, Vladimir Belenkiy, D. Trushnikov, S. Varushkin, Pang Shengyong
Introduction. At present, additive technologies are actively developing all over the world and are becoming more and more widely used in industrial production. The use of electron beams in additive processes of directed energy input, the so-called Directed Energy Deposition (DED) technologies, has several advantages, the main ones being the flexibility of controlling the spatial and energy characteristics of the thermal source and the presence of a vacuum protective environment. The standard scheme for additive electron beam deposition is melting of a wire filler material fed from the side into the electron beam affected area, but this additive electron beam deposition pattern does not provide a uniform thermal impact in the deposited area. The most effective method for electron-beam deposition is vertical wire feeding, which provides the most stable formation of the liquid metal bath and, consequently, the deposited beads. At the same time, so far there are no results of numerical analysis of this process in order to determine its main regularities. The aim of the work is to carry out numerical experiments for qualitative analysis and determination of the regularities of formation of deposited beads and transfer of filler material, the dependence of the geometric characteristics of the obtained beads on the influence of vapor pressure forces, direction and value of the azimuthal angle of heat sources. The research methods were a series of numerical experiments, which analyzed variants of the electron-beam surfacing process at the location of the surfacing rate vector in the action plane of electron beams and perpendicular to this plane to determine the basic regularities of deposited beads formation and transfer of filler material, dependence of geometric characteristics of obtained beads on the influence of vapor pressure forces, direction of heat sources and the azimuth angle of heat sources. Results and discussion. It is found that the geometric characteristics of the deposited beads significantly depend on the relative position of the deposition velocity vector with respect to the plane of the electron beams, and consideration of the vapor pressure has a significant influence on the results of numerical simulation of the weld pool formation and the hydrodynamic processes occurring in it. In this case, the location of the deposition velocity vector perpendicular to the action plane of the electron beams, there is a more uniform geometry of the deposited metal beads, and increasing the azimuthal angle of the heat sources increases the probability of spitting to the periphery of the deposited bead, which is associated with limitation of the melt motion in the longitudinal direction by the vapor pressure forces.
{"title":"Numerical analysis of the process of electron beam additive deposition with vertical feed of wire material","authors":"G. Permyakov, R. Davlyatshin, Vladimir Belenkiy, D. Trushnikov, S. Varushkin, Pang Shengyong","doi":"10.17212/1994-6309-2022-24.3-6-21","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.3-6-21","url":null,"abstract":"Introduction. At present, additive technologies are actively developing all over the world and are becoming more and more widely used in industrial production. The use of electron beams in additive processes of directed energy input, the so-called Directed Energy Deposition (DED) technologies, has several advantages, the main ones being the flexibility of controlling the spatial and energy characteristics of the thermal source and the presence of a vacuum protective environment. The standard scheme for additive electron beam deposition is melting of a wire filler material fed from the side into the electron beam affected area, but this additive electron beam deposition pattern does not provide a uniform thermal impact in the deposited area. The most effective method for electron-beam deposition is vertical wire feeding, which provides the most stable formation of the liquid metal bath and, consequently, the deposited beads. At the same time, so far there are no results of numerical analysis of this process in order to determine its main regularities. The aim of the work is to carry out numerical experiments for qualitative analysis and determination of the regularities of formation of deposited beads and transfer of filler material, the dependence of the geometric characteristics of the obtained beads on the influence of vapor pressure forces, direction and value of the azimuthal angle of heat sources. The research methods were a series of numerical experiments, which analyzed variants of the electron-beam surfacing process at the location of the surfacing rate vector in the action plane of electron beams and perpendicular to this plane to determine the basic regularities of deposited beads formation and transfer of filler material, dependence of geometric characteristics of obtained beads on the influence of vapor pressure forces, direction of heat sources and the azimuth angle of heat sources. Results and discussion. It is found that the geometric characteristics of the deposited beads significantly depend on the relative position of the deposition velocity vector with respect to the plane of the electron beams, and consideration of the vapor pressure has a significant influence on the results of numerical simulation of the weld pool formation and the hydrodynamic processes occurring in it. In this case, the location of the deposition velocity vector perpendicular to the action plane of the electron beams, there is a more uniform geometry of the deposited metal beads, and increasing the azimuthal angle of the heat sources increases the probability of spitting to the periphery of the deposited bead, which is associated with limitation of the melt motion in the longitudinal direction by the vapor pressure forces.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43323069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-15DOI: 10.17212/1994-6309-2022-24.3-76-89
A. Vorontsov, A. Filippov, N. Shamarin, E. Moskvichev, O. Novitskaya, Evgenii Knyazhev, Yu. I. Denisova, A. Leonov, V. Denisov
Introduction. The current state of the art in the field of hard coatings application requires the formation of nanostructured compositions using different chemical elements. Modern hard coatings are able to combine different properties such as high hardness, wear resistance, corrosion resistance. At present, coatings formed by layer-by-layer deposition of zirconium and chromium nitrides are promising. When depositing combinations of chemical elements on various substrates, studies are required aimed at investigating its microstructure and, mainly, residual stresses formed during the deposition of multilayer coatings. The purpose of this work is to investigate the structural-phase state and residual stresses of ZrN/CrN system coatings formed by plasma-assisted vacuum-arc method from the gas phase. Research methods. Samples with coatings of zirconium and chromium nitrides deposited on substrates of hard alloy VК8 are investigated. Transmission electron microscopy is used to study the microstructural characteristics of multilayered coatings and X-ray diffraction analysis is used to quantify macroscopic stresses. Results and discussion. Based on the experimental results obtained it is found that changing the modes of deposition of multilayer ZrN/CrN coatings with regard to rotation speeds of table and substrate holder leads to variations in microstructure, morphology and internal stresses of surface layers of multilayer coatings. It is shown that by changing conditions for the multilayer coating deposition the possibilities of forming ZrN/CrN coatings on the substrate made of VK8 alloy with nanoscale thickness of coating layers open up. X-ray diffraction analysis indicates mainly insignificant stresses, and at high table and substrate rotation speeds – high compressive stresses in the multilayer coating. Transmission electron microscopy revealed that CrN and ZrN coatings have a common multilayer coating growth texture at low rotation speeds, and at high speeds a textural misorientation of the phases of the coating layers is observed. Based on the results obtained it is possible to recommend coatings of ZrN/CrN system as hard coatings.
{"title":"Microstructure and residual stresses of ZrN/CrN multilayer coatings formed by the plasma-assisted vacuum-arc method","authors":"A. Vorontsov, A. Filippov, N. Shamarin, E. Moskvichev, O. Novitskaya, Evgenii Knyazhev, Yu. I. Denisova, A. Leonov, V. Denisov","doi":"10.17212/1994-6309-2022-24.3-76-89","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.3-76-89","url":null,"abstract":"Introduction. The current state of the art in the field of hard coatings application requires the formation of nanostructured compositions using different chemical elements. Modern hard coatings are able to combine different properties such as high hardness, wear resistance, corrosion resistance. At present, coatings formed by layer-by-layer deposition of zirconium and chromium nitrides are promising. When depositing combinations of chemical elements on various substrates, studies are required aimed at investigating its microstructure and, mainly, residual stresses formed during the deposition of multilayer coatings. The purpose of this work is to investigate the structural-phase state and residual stresses of ZrN/CrN system coatings formed by plasma-assisted vacuum-arc method from the gas phase. Research methods. Samples with coatings of zirconium and chromium nitrides deposited on substrates of hard alloy VК8 are investigated. Transmission electron microscopy is used to study the microstructural characteristics of multilayered coatings and X-ray diffraction analysis is used to quantify macroscopic stresses. Results and discussion. Based on the experimental results obtained it is found that changing the modes of deposition of multilayer ZrN/CrN coatings with regard to rotation speeds of table and substrate holder leads to variations in microstructure, morphology and internal stresses of surface layers of multilayer coatings. It is shown that by changing conditions for the multilayer coating deposition the possibilities of forming ZrN/CrN coatings on the substrate made of VK8 alloy with nanoscale thickness of coating layers open up. X-ray diffraction analysis indicates mainly insignificant stresses, and at high table and substrate rotation speeds – high compressive stresses in the multilayer coating. Transmission electron microscopy revealed that CrN and ZrN coatings have a common multilayer coating growth texture at low rotation speeds, and at high speeds a textural misorientation of the phases of the coating layers is observed. Based on the results obtained it is possible to recommend coatings of ZrN/CrN system as hard coatings.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47465421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-15DOI: 10.17212/1994-6309-2022-24.3-90-102
I. Ivanov, D. Safarova, Z. Bataeva, I. Bataev
Introduction. High-entropy alloys (HEAs) belong to a new and promising class of materials that are attracting the attention of both scientists and engineers from all over the world. Among all alloys of the AlxCoCrFeNi system, HEAs with x ≤ 0.3 attract special attention. Materials with this composition are characterized by the presence of only one phase with a face-centered cubic lattice (FCC). Such alloys have high ductility, excellent corrosion resistance and phase stability at high temperatures. The purpose of this work is to compare several methods of profile analysis on the example of plastically deformed ingots of a high-entropy Al0.3CoCrFeNi alloy. The methods of investigation. Using several methods of profile analysis of X-ray diffraction patterns, the structures of the cold-worked high-entropy alloy Al0.3CoCrFeNi are studied. In addition to the classical Williamson-Hall method, the analysis was carried out using a modified one, as well as a method that takes into account the anisotropy of the elastic properties of the crystal lattice. Research material. Ingots of the high-entropy Al0.3CoCrFeNi alloy deformed by cold rolling with a maximum reduction ratio of 80% were used as the object of the study. Samples were cut from the obtained blanks, which were studied by the method of synchrotron radiation diffraction according to the “transmission” scheme along two (longitudinal (RD) and transverse (TD)) directions of rolled products. Results and discussion. It is shown that the use of the classical Williamson-Hall method leads to a significant error in the approximation of experimental results. The modified Williamson-Hall method has the smallest approximation error and can be recommended for studying the Al0.3CoCrFeNi alloy. An analysis of deformed samples using this method made it possible to reveal several features of the formation of defects in the crystalline structure, which are in good agreement with the classical concepts of the mechanisms of plastic deformation. First, an increase in the degree of deformation of the high-entropy Al0.3CoCrFeNi alloy leads to an almost uniform increase in the number of twins and stacking faults. Secondly, with an increase in the degree of reduction, there is a decrease in the fraction of edge dislocations and an increase in the fraction of screw dislocations in the material. The results obtained correlate well with the results of microhardness measurements.
{"title":"Comparison of approaches based on the Williamson-Hall method for analyzing the structure of an Al0.3CoCrFeNi high-entropy alloy after cold deformation","authors":"I. Ivanov, D. Safarova, Z. Bataeva, I. Bataev","doi":"10.17212/1994-6309-2022-24.3-90-102","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.3-90-102","url":null,"abstract":"Introduction. High-entropy alloys (HEAs) belong to a new and promising class of materials that are attracting the attention of both scientists and engineers from all over the world. Among all alloys of the AlxCoCrFeNi system, HEAs with x ≤ 0.3 attract special attention. Materials with this composition are characterized by the presence of only one phase with a face-centered cubic lattice (FCC). Such alloys have high ductility, excellent corrosion resistance and phase stability at high temperatures. The purpose of this work is to compare several methods of profile analysis on the example of plastically deformed ingots of a high-entropy Al0.3CoCrFeNi alloy. The methods of investigation. Using several methods of profile analysis of X-ray diffraction patterns, the structures of the cold-worked high-entropy alloy Al0.3CoCrFeNi are studied. In addition to the classical Williamson-Hall method, the analysis was carried out using a modified one, as well as a method that takes into account the anisotropy of the elastic properties of the crystal lattice. Research material. Ingots of the high-entropy Al0.3CoCrFeNi alloy deformed by cold rolling with a maximum reduction ratio of 80% were used as the object of the study. Samples were cut from the obtained blanks, which were studied by the method of synchrotron radiation diffraction according to the “transmission” scheme along two (longitudinal (RD) and transverse (TD)) directions of rolled products. Results and discussion. It is shown that the use of the classical Williamson-Hall method leads to a significant error in the approximation of experimental results. The modified Williamson-Hall method has the smallest approximation error and can be recommended for studying the Al0.3CoCrFeNi alloy. An analysis of deformed samples using this method made it possible to reveal several features of the formation of defects in the crystalline structure, which are in good agreement with the classical concepts of the mechanisms of plastic deformation. First, an increase in the degree of deformation of the high-entropy Al0.3CoCrFeNi alloy leads to an almost uniform increase in the number of twins and stacking faults. Secondly, with an increase in the degree of reduction, there is a decrease in the fraction of edge dislocations and an increase in the fraction of screw dislocations in the material. The results obtained correlate well with the results of microhardness measurements.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44204798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-15DOI: 10.17212/1994-6309-2022-24.3-103-111
Dmitry Kryukov
Introduction. Monometallic armor traditionally used in military and special equipment armaments has a number of key disadvantages that have a significant impact on the tactical and technical characteristics of the products, namely, significant weight and thickness. At the same time, composite non-metallic armors, which have been widely used recently as an alternative, in turn, are not able to withstand multiple hits in local areas of the structure due to its complete destruction or delamination. The purpose of the work: to develop the technology of obtaining a new class of multilayer metal armor materials based on light metals and alloys by explosive welding, combining high indicators of bullet resistance and structural strength along with low specific gravity. The work presents a new scheme for reinforcing the composite using explosive welding technology, which allows localizing the development of brittle cracks along interlayer boundaries with external ballistic impact on the object. Results and discussion. Reinforced composite material based on titanium and aluminum alloys is obtained by explosive welding. Rational modes of shock-wave loading, which ensure production of composite material of required quality are determined; evaluation of strength of composite is carried out. In order to improve the tactical and technical characteristics of the composite, it was proposed to form high-solid intermetallic layers in its structure due to heat treatment. Rational modes of high-temperature annealing are defined, which ensure formation of intermetallic layers of preset thickness in composite structure. The phase composition of intermetallic pro-layers is studied. Structural features of the composite material are investigated. Mechanism of brittle cracks localization in composite structure at ballistic impact on it is described.
{"title":"Structural features and technology of light armor composite materials with mechanism of brittle cracks localization","authors":"Dmitry Kryukov","doi":"10.17212/1994-6309-2022-24.3-103-111","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.3-103-111","url":null,"abstract":"Introduction. Monometallic armor traditionally used in military and special equipment armaments has a number of key disadvantages that have a significant impact on the tactical and technical characteristics of the products, namely, significant weight and thickness. At the same time, composite non-metallic armors, which have been widely used recently as an alternative, in turn, are not able to withstand multiple hits in local areas of the structure due to its complete destruction or delamination. The purpose of the work: to develop the technology of obtaining a new class of multilayer metal armor materials based on light metals and alloys by explosive welding, combining high indicators of bullet resistance and structural strength along with low specific gravity. The work presents a new scheme for reinforcing the composite using explosive welding technology, which allows localizing the development of brittle cracks along interlayer boundaries with external ballistic impact on the object. Results and discussion. Reinforced composite material based on titanium and aluminum alloys is obtained by explosive welding. Rational modes of shock-wave loading, which ensure production of composite material of required quality are determined; evaluation of strength of composite is carried out. In order to improve the tactical and technical characteristics of the composite, it was proposed to form high-solid intermetallic layers in its structure due to heat treatment. Rational modes of high-temperature annealing are defined, which ensure formation of intermetallic layers of preset thickness in composite structure. The phase composition of intermetallic pro-layers is studied. Structural features of the composite material are investigated. Mechanism of brittle cracks localization in composite structure at ballistic impact on it is described.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47008767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-15DOI: 10.17212/1994-6309-2022-24.3-66-75
V. Stolyarov, V. Andreev, R. Karelin, U. Ugurchiev, V. Cherkasov, V. Komarov, V. Yusupov
Introduction. The deformation capacity of materials is one of the main mechanical characteristics that determine the possibility of its production using various technological processes for metal forming. Among intermetallic compounds, a special role belongs to alloys with a high-temperature shape memory effect (SME) based on TiNi with the addition hafnium. Most of these alloys are not only difficult to deform, but also quite brittle. Therefore, the development of any technological schemes to increase the deformation capacity of these alloys is relevant. The purpose of the work: to study the deformation capacity and the possibility of using electric pulsed current during cold rolling of the TiNiHf alloy. This processing method has not previously been applied to these alloys. In this work, the deformation capacity during cold rolling of a strip 2 mm thick made of a hard-to-deform high-temperature TiNi-based shape memory alloy with the addition of hafnium is studied. To increase the deformability, an external action in the form of a high-density pulsed current of more than 200 A/mm2 is investigated. The research methods are: X-ray analysis to assess the initial phase state; analysis of the evolution of true and engineering deformation to failure (appearance of visible macrocracks in the deformation zone); optical microscopy with magnification from 50 to 100 and measurement of Vickers hardness at room temperature. Results and discussion. An increase in the deformability under the influence of a pulsed current compared to rolling without current and the achievement of a maximum strain of 1.7 (true) and 85% (engineering) are established. The initial coarse-grained equiaxed martensitic microstructure (50 μm) is transformed into a microstructure elongated along the rolling direction, while the hardness increases by 50%. The absence of noticeable structural changes and the observed hardening may indicate a nonthermal effect of the current in increasing the deformability. Thus, the results of the conducted studies indicate the prospects of the method of rolling with a current of a hard-to-deform TiNiHf shape memory alloy as a method of metal forming.
{"title":"Deformability of TiNiHf shape memory alloy under rolling with pulsed current","authors":"V. Stolyarov, V. Andreev, R. Karelin, U. Ugurchiev, V. Cherkasov, V. Komarov, V. Yusupov","doi":"10.17212/1994-6309-2022-24.3-66-75","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.3-66-75","url":null,"abstract":"Introduction. The deformation capacity of materials is one of the main mechanical characteristics that determine the possibility of its production using various technological processes for metal forming. Among intermetallic compounds, a special role belongs to alloys with a high-temperature shape memory effect (SME) based on TiNi with the addition hafnium. Most of these alloys are not only difficult to deform, but also quite brittle. Therefore, the development of any technological schemes to increase the deformation capacity of these alloys is relevant. The purpose of the work: to study the deformation capacity and the possibility of using electric pulsed current during cold rolling of the TiNiHf alloy. This processing method has not previously been applied to these alloys. In this work, the deformation capacity during cold rolling of a strip 2 mm thick made of a hard-to-deform high-temperature TiNi-based shape memory alloy with the addition of hafnium is studied. To increase the deformability, an external action in the form of a high-density pulsed current of more than 200 A/mm2 is investigated. The research methods are: X-ray analysis to assess the initial phase state; analysis of the evolution of true and engineering deformation to failure (appearance of visible macrocracks in the deformation zone); optical microscopy with magnification from 50 to 100 and measurement of Vickers hardness at room temperature. Results and discussion. An increase in the deformability under the influence of a pulsed current compared to rolling without current and the achievement of a maximum strain of 1.7 (true) and 85% (engineering) are established. The initial coarse-grained equiaxed martensitic microstructure (50 μm) is transformed into a microstructure elongated along the rolling direction, while the hardness increases by 50%. The absence of noticeable structural changes and the observed hardening may indicate a nonthermal effect of the current in increasing the deformability. Thus, the results of the conducted studies indicate the prospects of the method of rolling with a current of a hard-to-deform TiNiHf shape memory alloy as a method of metal forming.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44611962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-15DOI: 10.17212/1994-6309-2022-24.3-40-52
S. Chinchanikar
Introduction. Over the last decade, composite materials based on polytetrafluoroethylene (PTFE) have been increasingly used as alternative materials for automotive applications. PTFE is characterized by a low coefficient of friction, hardness and corrosion resistance. However, this material has a high wear rate. A group of researchers attempted to improve the wear resistance of PTFE material by reinforcing it with different fillers. The purpose of the work: This study experimentally investigates the dry sliding wear characteristics of a PTFE composite reinforced with carbon fiber (35 wt.%) compared to SS304 stainless steel. In addition, experimental mathematical and ANN models are developed to predict the specific wear rate, taking into account the influence of pressure, sliding speed, and interface temperature. The methods of investigation. Dry sliding experiments were performed on a pin-on-disk wear testing machine with varying the normal load on the pin, disk rotation, and interface temperature. Experiments were planned systematically to investigate the effect of input parameters on specific wear rates with a wide range of design space. In total, fifteen experiments were carried out at a 5-kilometer distance without repeating the central run experiment. Sliding velocities were obtained by selecting the track diameter on the disk and corresponding rotation of the disk. A feedforward back-propagation machine learning algorithm was used to the ANN model. Results and Discussion. This study finds better prediction accuracy with the ANN architecture having two hidden layers with 150 neurons on each layer. This study finds an increase in specific wear rates with normal load, sliding velocity, and interface temperature. However, the increase is more prominent at higher process parameters. The normal load followed by sliding velocity most significantly affects the specific wear rate. The results predicted by the developed models for specific wear rates are in good agreement with the experimental values with an average error close to 10%. This shows that the model could be reliably used to obtain the wear rate of PTFE composite reinforced with carbon fiber (35 wt.%) compared to SS304 stainless steel. This study finds scope for further studies considering the effect of varying ANN architectures, different amount of neurons, and hidden layers on the prediction accuracy of the wear rate.
{"title":"Modeling of sliding wear characteristics of Polytetrafluoroethylene (PTFE) composite reinforced with carbon fiber against SS304","authors":"S. Chinchanikar","doi":"10.17212/1994-6309-2022-24.3-40-52","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.3-40-52","url":null,"abstract":"Introduction. Over the last decade, composite materials based on polytetrafluoroethylene (PTFE) have been increasingly used as alternative materials for automotive applications. PTFE is characterized by a low coefficient of friction, hardness and corrosion resistance. However, this material has a high wear rate. A group of researchers attempted to improve the wear resistance of PTFE material by reinforcing it with different fillers. The purpose of the work: This study experimentally investigates the dry sliding wear characteristics of a PTFE composite reinforced with carbon fiber (35 wt.%) compared to SS304 stainless steel. In addition, experimental mathematical and ANN models are developed to predict the specific wear rate, taking into account the influence of pressure, sliding speed, and interface temperature. The methods of investigation. Dry sliding experiments were performed on a pin-on-disk wear testing machine with varying the normal load on the pin, disk rotation, and interface temperature. Experiments were planned systematically to investigate the effect of input parameters on specific wear rates with a wide range of design space. In total, fifteen experiments were carried out at a 5-kilometer distance without repeating the central run experiment. Sliding velocities were obtained by selecting the track diameter on the disk and corresponding rotation of the disk. A feedforward back-propagation machine learning algorithm was used to the ANN model. Results and Discussion. This study finds better prediction accuracy with the ANN architecture having two hidden layers with 150 neurons on each layer. This study finds an increase in specific wear rates with normal load, sliding velocity, and interface temperature. However, the increase is more prominent at higher process parameters. The normal load followed by sliding velocity most significantly affects the specific wear rate. The results predicted by the developed models for specific wear rates are in good agreement with the experimental values with an average error close to 10%. This shows that the model could be reliably used to obtain the wear rate of PTFE composite reinforced with carbon fiber (35 wt.%) compared to SS304 stainless steel. This study finds scope for further studies considering the effect of varying ANN architectures, different amount of neurons, and hidden layers on the prediction accuracy of the wear rate.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48375317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-15DOI: 10.17212/1994-6309-2022-24.3-22-39
A. Ilinykh, V. Banul, D. Vorontsov
Introduction. There are different rail machining technologies designed to eliminate defects on the tread surface and extend the life cycle of rails. The most used is the technology of grinding rails with rotating grinding wheels using rail-grinding trains. Its main disadvantage is the low working speed of the grinding train that requires the organization of track possessions with stopping the movement of trains along the haul. To perform preventive rail grinding with minimal metal removal from the rail head, passive grinding technologies using grinding wheels have become widespread in last years. Passive grinding is when there is no power on the grinding wheel to rotate it actively. Such methods make it possible to achieve high speeds of the grinding train, and the work can be carried out in the train schedule without closing the stage. Currently, passive grinding technologies are relatively new and do not have the necessary scientific basis for optimizing the machining process. The aim of the work is to perform theoretical studies of kinematic and force analyzes of two methods of rail passive grinding: the periphery and the end face of the grinding wheel. Methodology of the work is kinematic and power calculations of rail grinding schemes. Results and discussion. Within the framework of theoretical studies, a kinematic and force analysis of two methods of passive grinding are carried out, on the basis of which the optimal conditions for its implementation are determined. It is established that the method of passive grinding by the periphery of the wheel has a 20 % higher productivity and energy efficiency of the process before end passive grinding due to the higher rotation speed of the grinding wheel with equal forces of pressing it to the rail. At the same time, passive grinding with the end of the wheel is distinguished by a twice greater range of change in both the speed of the grinding wheel rotation and the force of its pressing that makes it possible to achieve greater metal removal at equal speeds of the grinding trains. In conclusion, promising tasks for further research in the field of passive rail grinding are formulated.
{"title":"Theoretical analysis of passive rail grinding","authors":"A. Ilinykh, V. Banul, D. Vorontsov","doi":"10.17212/1994-6309-2022-24.3-22-39","DOIUrl":"https://doi.org/10.17212/1994-6309-2022-24.3-22-39","url":null,"abstract":"Introduction. There are different rail machining technologies designed to eliminate defects on the tread surface and extend the life cycle of rails. The most used is the technology of grinding rails with rotating grinding wheels using rail-grinding trains. Its main disadvantage is the low working speed of the grinding train that requires the organization of track possessions with stopping the movement of trains along the haul. To perform preventive rail grinding with minimal metal removal from the rail head, passive grinding technologies using grinding wheels have become widespread in last years. Passive grinding is when there is no power on the grinding wheel to rotate it actively. Such methods make it possible to achieve high speeds of the grinding train, and the work can be carried out in the train schedule without closing the stage. Currently, passive grinding technologies are relatively new and do not have the necessary scientific basis for optimizing the machining process. The aim of the work is to perform theoretical studies of kinematic and force analyzes of two methods of rail passive grinding: the periphery and the end face of the grinding wheel. Methodology of the work is kinematic and power calculations of rail grinding schemes. Results and discussion. Within the framework of theoretical studies, a kinematic and force analysis of two methods of passive grinding are carried out, on the basis of which the optimal conditions for its implementation are determined. It is established that the method of passive grinding by the periphery of the wheel has a 20 % higher productivity and energy efficiency of the process before end passive grinding due to the higher rotation speed of the grinding wheel with equal forces of pressing it to the rail. At the same time, passive grinding with the end of the wheel is distinguished by a twice greater range of change in both the speed of the grinding wheel rotation and the force of its pressing that makes it possible to achieve greater metal removal at equal speeds of the grinding trains. In conclusion, promising tasks for further research in the field of passive rail grinding are formulated.","PeriodicalId":42889,"journal":{"name":"Obrabotka Metallov-Metal Working and Material Science","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49593044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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