The analysis of waste generation from the production of chromium-containing ferroalloys in the Russian Federation is carried out.Representative samples of slags and dusts were selected from the production of chromium ferroalloys, depending on the grade composition and the technological equipment used.The chemical and phase compositions of the samples were studied.The fractional composition of self-disintegrating slags and dusts was studied by the method of dynamic analysis of digital images.Physicochemical characteristics were experimentally investigated: density, melting points, viscosity of selected samples. Wastes from the production of various grades of chromium ferroalloys have their own specific compositions and properties. The melting temperature range of the studied samples varies in a wide range and differs significantly for each of them. Dusts from gas cleaning of high-carbon ferrochrome have the lowest melting points (1460 - 1480 ºС). Dust from cyclones and low-carbon ferrochrome gas cleaning have the highest melting temperature ranges reaching 1790 ºС. According to its characteristics, waste of chrome production can be used in small quantities (up to 10%) as additives in the production of ferroalloys of other grades. Waste from chromium production can be more efficiently used in the production of refractory products and materials for ferrous metallurgy.
{"title":"The Study of the Characteristics and Possibilities of Using Slags and Dusts from Ferrochrome Production","authors":"V. Zhuchkov, O. Zayakin, A. Sychev","doi":"10.2139/ssrn.3927672","DOIUrl":"https://doi.org/10.2139/ssrn.3927672","url":null,"abstract":"The analysis of waste generation from the production of chromium-containing ferroalloys in the Russian Federation is carried out.Representative samples of slags and dusts were selected from the production of chromium ferroalloys, depending on the grade composition and the technological equipment used.The chemical and phase compositions of the samples were studied.The fractional composition of self-disintegrating slags and dusts was studied by the method of dynamic analysis of digital images.Physicochemical characteristics were experimentally investigated: density, melting points, viscosity of selected samples. Wastes from the production of various grades of chromium ferroalloys have their own specific compositions and properties. The melting temperature range of the studied samples varies in a wide range and differs significantly for each of them. Dusts from gas cleaning of high-carbon ferrochrome have the lowest melting points (1460 - 1480 ºС). Dust from cyclones and low-carbon ferrochrome gas cleaning have the highest melting temperature ranges reaching 1790 ºС. According to its characteristics, waste of chrome production can be used in small quantities (up to 10%) as additives in the production of ferroalloys of other grades. Waste from chromium production can be more efficiently used in the production of refractory products and materials for ferrous metallurgy.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83939189","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 : 2021-08-26DOI: 10.15587/1729-4061.2021.233349
A. Taufik, P. Pratikto, A. Suprapto, A. A. Sonief
This paper wants to know the effect of bending radius on the distribution of hardness, grain distribution and microstructure on the surface area of tensile stress and compressive stress after bending, quenching and tempering. Material testing helps determine and analyze material quality. The research was conducted on the bending of Hot Rolled Plate Steel material with a radius of 50 mm, 55 mm, 60 mm, 65 mm and 70 mm with a measurement distance of 1 mm, 2 mm and 3 mm, the highest value was obtained at a radius of 55 mm with a measurement distance of 1 mm. After getting the quench-temper treatment with a holding time of 30 minutes, the value of 498 HV was obtained at a radius of 70 mm with a measurement distance of 2 mm. Hardness test was performed using the austenite temperature of 900 °С, microstructure test results obtained finer grains in the compression area r=2.173 µm and in the tensile area r=2.34 µm. This observation aims to determine the microstructure of the material undergoing a heat treatment process at a temperature of 900 °С with a holding time of 30 minutes using water cooling media. The results of the observation of the microstructure of the test specimens before the quench-temper process showed that the structure of ferrite was more abundant than perlite, but after the quench-tempering process the results showed that there was more perlite than ferrite due to the presence of austenite. The treatment on the transformation of the Ar3 line causes the hardness to change the shape of the martensite microstructure into steel while the thickness of the carburizing layer increases with the increase in the carbonization temperature on the surface of the quenched specimen, resulting in the formation of martensite and residual austenite causing the coating to become hard.
{"title":"Analysis of the Influence of Hot Rolled Plate Steel Treatment Using Temper and Quench-Temper Method on Vickers Hardness Number Enhancement","authors":"A. Taufik, P. Pratikto, A. Suprapto, A. A. Sonief","doi":"10.15587/1729-4061.2021.233349","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.233349","url":null,"abstract":"This paper wants to know the effect of bending radius on the distribution of hardness, grain distribution and microstructure on the surface area of tensile stress and compressive stress after bending, quenching and tempering. Material testing helps determine and analyze material quality. The research was conducted on the bending of Hot Rolled Plate Steel material with a radius of 50 mm, 55 mm, 60 mm, 65 mm and 70 mm with a measurement distance of 1 mm, 2 mm and 3 mm, the highest value was obtained at a radius of 55 mm with a measurement distance of 1 mm. After getting the quench-temper treatment with a holding time of 30 minutes, the value of 498 HV was obtained at a radius of 70 mm with a measurement distance of 2 mm. Hardness test was performed using the austenite temperature of 900 °С, microstructure test results obtained finer grains in the compression area r=2.173 µm and in the tensile area r=2.34 µm. This observation aims to determine the microstructure of the material undergoing a heat treatment process at a temperature of 900 °С with a holding time of 30 minutes using water cooling media. The results of the observation of the microstructure of the test specimens before the quench-temper process showed that the structure of ferrite was more abundant than perlite, but after the quench-tempering process the results showed that there was more perlite than ferrite due to the presence of austenite. The treatment on the transformation of the Ar3 line causes the hardness to change the shape of the martensite microstructure into steel while the thickness of the carburizing layer increases with the increase in the carbonization temperature on the surface of the quenched specimen, resulting in the formation of martensite and residual austenite causing the coating to become hard.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88172513","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}
Abstract In this research, mixed structures are created so that they have regions where dislocations accumulate and a region that is, to some extent, free from dislocations. These heterogeneous structures that bring together both soft and hard domains in a single sample are presumed to produce a fine recrystallized grain and recovered large grain structures if they are subsequently heated, leading to limited recrystallization. In the present work, the 3D Potts model has been modified to tailor and model complex problems such as heterogeneous structure recrystallization. This is done by introducing a limited fraction of nucleating grains to the structure where the highest geometrically necessary dislocation density distributions develop in the rolled layers at early simulation time as well as by controlling structure evolution in the undeformed structure layer using grain boundary energy criteria. Additionally, the designed microstructures were investigated using electron backscatter diffraction measurements and an in-situ heating stage performed on material with various degrees of deformation.
{"title":"Analyzing Recrystallization Behavior of Heterogeneous Structures Single-Phase Al Alloys","authors":"Khaled Adam, D. Field","doi":"10.2139/ssrn.3859735","DOIUrl":"https://doi.org/10.2139/ssrn.3859735","url":null,"abstract":"Abstract In this research, mixed structures are created so that they have regions where dislocations accumulate and a region that is, to some extent, free from dislocations. These heterogeneous structures that bring together both soft and hard domains in a single sample are presumed to produce a fine recrystallized grain and recovered large grain structures if they are subsequently heated, leading to limited recrystallization. In the present work, the 3D Potts model has been modified to tailor and model complex problems such as heterogeneous structure recrystallization. This is done by introducing a limited fraction of nucleating grains to the structure where the highest geometrically necessary dislocation density distributions develop in the rolled layers at early simulation time as well as by controlling structure evolution in the undeformed structure layer using grain boundary energy criteria. Additionally, the designed microstructures were investigated using electron backscatter diffraction measurements and an in-situ heating stage performed on material with various degrees of deformation.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89631107","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}
Abstract Optimizing the composition and improving the conflicting mechanical and electrical properties of multiple complex alloys has always been difficult by traditional trial-and-error methods. Here we propose a machine learning strategy to design alloys with remarkable properties by screening key alloy factors through correlation screening, recursive elimination and exhaustive screening, and then designing composition iteratively through Bayesian optimization. Taking the precipitation strengthened copper alloys as an example, 5 kinds of key alloy factors affecting hardness (HV) and 6 kinds of key alloy factors affecting electrical conductivity (EC) were obtained by screening alloy factors. “HV - key alloy factors” model with error less than 7% and the “EC - key alloy factors” model with error less than 9% were established, respectively. Then, new copper alloys were effectively designed utilizing Bayesian optimization and iterative optimization experiments. Designed Cu-1.3Ni-1.4Co-0.56Si-0.03Mg alloy has excellent combined mechanical and electrical properties with the measured ultimate tensile strength (UTS) of 858 MPa and EC of 47.6%IACS. The property results are superior to the reported precipitation strengthened copper alloys, which realize the simultaneous improvement of the conflicting mechanical and electrical properties.
{"title":"Machine Learning Assisted Composition Effective Design for Precipitation Strengthened Copper Alloys","authors":"Hongtao Zhang, Huadong Fu, Shuaicheng Zhu, Wei Yong, Jian-Xin Xie","doi":"10.2139/ssrn.3826667","DOIUrl":"https://doi.org/10.2139/ssrn.3826667","url":null,"abstract":"Abstract Optimizing the composition and improving the conflicting mechanical and electrical properties of multiple complex alloys has always been difficult by traditional trial-and-error methods. Here we propose a machine learning strategy to design alloys with remarkable properties by screening key alloy factors through correlation screening, recursive elimination and exhaustive screening, and then designing composition iteratively through Bayesian optimization. Taking the precipitation strengthened copper alloys as an example, 5 kinds of key alloy factors affecting hardness (HV) and 6 kinds of key alloy factors affecting electrical conductivity (EC) were obtained by screening alloy factors. “HV - key alloy factors” model with error less than 7% and the “EC - key alloy factors” model with error less than 9% were established, respectively. Then, new copper alloys were effectively designed utilizing Bayesian optimization and iterative optimization experiments. Designed Cu-1.3Ni-1.4Co-0.56Si-0.03Mg alloy has excellent combined mechanical and electrical properties with the measured ultimate tensile strength (UTS) of 858 MPa and EC of 47.6%IACS. The property results are superior to the reported precipitation strengthened copper alloys, which realize the simultaneous improvement of the conflicting mechanical and electrical properties.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77042577","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}
Abstract The mechanical properties of crystalline materials can be efficiently optimized using a hierarchical twinned structure. Conventional deformation mechanisms for coherent Σ3 boundaries generally involve three basic models: cross-slip, partial dislocation step, and full dislocation step. In this study, we report a novel deformation mechanism that allows the co-existence of twin-separation, phase transformations, grain rotation, and cracking, around a triple junction of twin boundaries in a hierarchical twinned high-entropy alloy. The deformation mechanisms in the reference high-entropy alloy (Fe-30Mn-10Co-10Cr at. %) were investigated using LAADF-STEM. The triple junction of the hierarchical twinned structure gradually deformed during in-situ strain and showed mechanisms significantly different from that observed in the purely twinned structures. These new mechanisms are referred to as “novel synergetic deformation mechanisms of hierarchical twin boundaries.” Understanding the fundamental mechanisms of the hierarchical twin boundaries under deformation could assist the design of strong and ductile bulk materials with hierarchical twinned structure.
{"title":"Synergetic Deformation Mechanism in Hierarchical Twinned High-Entropy Alloys","authors":"Wenjun Lu, Jianjun Li","doi":"10.2139/ssrn.3834125","DOIUrl":"https://doi.org/10.2139/ssrn.3834125","url":null,"abstract":"Abstract The mechanical properties of crystalline materials can be efficiently optimized using a hierarchical twinned structure. Conventional deformation mechanisms for coherent Σ3 boundaries generally involve three basic models: cross-slip, partial dislocation step, and full dislocation step. In this study, we report a novel deformation mechanism that allows the co-existence of twin-separation, phase transformations, grain rotation, and cracking, around a triple junction of twin boundaries in a hierarchical twinned high-entropy alloy. The deformation mechanisms in the reference high-entropy alloy (Fe-30Mn-10Co-10Cr at. %) were investigated using LAADF-STEM. The triple junction of the hierarchical twinned structure gradually deformed during in-situ strain and showed mechanisms significantly different from that observed in the purely twinned structures. These new mechanisms are referred to as “novel synergetic deformation mechanisms of hierarchical twin boundaries.” Understanding the fundamental mechanisms of the hierarchical twin boundaries under deformation could assist the design of strong and ductile bulk materials with hierarchical twinned structure.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"136 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73288430","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 : 2021-08-01DOI: 10.20998/2074-272x.2021.4.02
V. Milykh, M. G. Tymin
Introduction: Three-phase inductors of a rotating magnetic field are used in grinders, separators and stirrers for the technological processing of bulk and liquid substances. This occurs in a cylindrical working chamber under the influence of ferromagnetic elements in the form of pieces of iron wire, which move together with the field. Problem: By analogy with three-phase induction motors, for the stator of inductors a concentric winding is adopted, which is a diametric single-layer winding. When moving from such motors to an inductor, its operating conditions have changed due to the significantly increased non-magnetic space inside the inductor compared to the motor clearances. The difference in the frontal parts of the phase windings has become essential for the electromagnetic parameters and the structure of the magnetic field in the inductor working chamber. Therefore, a loop shortened stator winding, which is symmetrical, can be considered as an alternative to a concentric diametric winding. Goal: The aim of the work is to compare the dimensional and electromagnetic parameters of a rotating magnetic field inductor in two versions of its three-phase winding: concentric single-layer diametrical and loop shortened two-layer. Methodology: Comparison of the windings is carried out through a detailed analysis of the geometrical parameters of their frontal parts, as well as through numerical-field calculations of the electromagnetic parameters of the inductor as a whole and the distribution of the magnetic field in its working chamber. Results: A significant difference in the geometrical parameters of the frontal parts of the two windings under inductor conditions was revealed. The loop version of the winding makes it possible to reduce the length of the winding conductor, its active resistance, as well as the reactance of its frontal dissipation. At the same time the asymmetry of the phase windings is excluded and an increase in the homogeneity of the magnetic field in the inductor working chamber is provided. Originality. The scientific novelty of the work lies in the development of a method of comparative analysis of the windings under the conditions of the rotating magnetic field inductor and in revealing the advantages of a loop shortened winding compared to the used concentric diametric winding. Practical value: The loop shortened stator winding recommended for the inductor will eliminate the asymmetry of its electromagnetic system. Thereby, the quality of its work in the technological processing of different substances is significantly increased due to ensuring the homogeneity of the magnetic field in the working chamber. At the same time, the copper conductor of the winding is still saved, and the efficiency of the inductor is also increased by reducing the power of electrical losses.
{"title":"A Comparative Analysis of the Parameters of a Rotating Magnetic Field Inductor When Using Concentric and Loop Windings","authors":"V. Milykh, M. G. Tymin","doi":"10.20998/2074-272x.2021.4.02","DOIUrl":"https://doi.org/10.20998/2074-272x.2021.4.02","url":null,"abstract":"Introduction: Three-phase inductors of a rotating magnetic field are used in grinders, separators and stirrers for the technological processing of bulk and liquid substances. This occurs in a cylindrical working chamber under the influence of ferromagnetic elements in the form of pieces of iron wire, which move together with the field. Problem: By analogy with three-phase induction motors, for the stator of inductors a concentric winding is adopted, which is a diametric single-layer winding. When moving from such motors to an inductor, its operating conditions have changed due to the significantly increased non-magnetic space inside the inductor compared to the motor clearances. The difference in the frontal parts of the phase windings has become essential for the electromagnetic parameters and the structure of the magnetic field in the inductor working chamber. Therefore, a loop shortened stator winding, which is symmetrical, can be considered as an alternative to a concentric diametric winding. Goal: The aim of the work is to compare the dimensional and electromagnetic parameters of a rotating magnetic field inductor in two versions of its three-phase winding: concentric single-layer diametrical and loop shortened two-layer. Methodology: Comparison of the windings is carried out through a detailed analysis of the geometrical parameters of their frontal parts, as well as through numerical-field calculations of the electromagnetic parameters of the inductor as a whole and the distribution of the magnetic field in its working chamber. Results: A significant difference in the geometrical parameters of the frontal parts of the two windings under inductor conditions was revealed. The loop version of the winding makes it possible to reduce the length of the winding conductor, its active resistance, as well as the reactance of its frontal dissipation. At the same time the asymmetry of the phase windings is excluded and an increase in the homogeneity of the magnetic field in the inductor working chamber is provided. Originality. The scientific novelty of the work lies in the development of a method of comparative analysis of the windings under the conditions of the rotating magnetic field inductor and in revealing the advantages of a loop shortened winding compared to the used concentric diametric winding. Practical value: The loop shortened stator winding recommended for the inductor will eliminate the asymmetry of its electromagnetic system. Thereby, the quality of its work in the technological processing of different substances is significantly increased due to ensuring the homogeneity of the magnetic field in the working chamber. At the same time, the copper conductor of the winding is still saved, and the efficiency of the inductor is also increased by reducing the power of electrical losses.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75663209","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 : 2021-07-27DOI: 10.15587/2706-5448.2021.237250
V. Trush, A. Luk’yanenko, V. Fedirko
The object of research is the analytical description of the phenomena in the near-surface layer, which are caused by the interaction of titanium with oxygen at high temperatures. These are temperatures that exceed the polymorphic transformation of the metal. High-temperature oxidation gives titanium products unique performance properties. Of course, such characteristics are determined, first of all, by the state of the near-surface layer. Therefore, an understanding of oxidation processes will make it possible to predict the state of the near-surface layer after heat treatment. However, to date, no unified approach has been created to describe the mechanism and kinetics of high-temperature oxidation of titanium in the near-surface layer. Indeed, most of the existing approaches make it possible to predict the nature of oxidation in the bulk of the metal. Some scientific papers describe the kinetics of oxidation, taking into account only the formation and growth of oxide layers. However, simultaneously with oxide formation, a diffusion zone is formed, which significantly affects the kinetics. Therefore, today one of the most problematic areas of high-temperature titanium oxidation is the description of the processes that take place in the near-surface layer. In this work, to describe the kinetics of high-temperature oxidation of titanium, in addition to the formation and growth of the oxide layer, the formation and growth of the diffusion zone is taken into account. In the diffusion zone, under the influence of structural phase transformations, solid solutions of oxygen are formed in the alpha and beta phases. This approach made it possible to take into account additional factors and thereby more accurately describe the processes of high-temperature oxidation of titanium. As a result of the calculations, the thickness of the oxide layer of the diffusion zone is given depending on the oxygen concentration and the duration of treatment. And also the dependences of the kinetics of displacement of the boundary of the oxide-diffusion layer are given and a system of equations for calculating the ratio of the formed phase components is developed. Thanks to the proposed analytical approach, it will be possible to calculate the sizes of interphase boundaries on the basis of temperature-time parameters and oxygen concentration and thereby form a hardened near-surface layer with certain functional properties.
{"title":"Study of Titanium Oxidation Kinetics at Temperature Above Polymorphic Transformation","authors":"V. Trush, A. Luk’yanenko, V. Fedirko","doi":"10.15587/2706-5448.2021.237250","DOIUrl":"https://doi.org/10.15587/2706-5448.2021.237250","url":null,"abstract":"The object of research is the analytical description of the phenomena in the near-surface layer, which are caused by the interaction of titanium with oxygen at high temperatures. These are temperatures that exceed the polymorphic transformation of the metal. High-temperature oxidation gives titanium products unique performance properties. Of course, such characteristics are determined, first of all, by the state of the near-surface layer. Therefore, an understanding of oxidation processes will make it possible to predict the state of the near-surface layer after heat treatment. However, to date, no unified approach has been created to describe the mechanism and kinetics of high-temperature oxidation of titanium in the near-surface layer. Indeed, most of the existing approaches make it possible to predict the nature of oxidation in the bulk of the metal. Some scientific papers describe the kinetics of oxidation, taking into account only the formation and growth of oxide layers. However, simultaneously with oxide formation, a diffusion zone is formed, which significantly affects the kinetics. Therefore, today one of the most problematic areas of high-temperature titanium oxidation is the description of the processes that take place in the near-surface layer. In this work, to describe the kinetics of high-temperature oxidation of titanium, in addition to the formation and growth of the oxide layer, the formation and growth of the diffusion zone is taken into account. In the diffusion zone, under the influence of structural phase transformations, solid solutions of oxygen are formed in the alpha and beta phases. This approach made it possible to take into account additional factors and thereby more accurately describe the processes of high-temperature oxidation of titanium. As a result of the calculations, the thickness of the oxide layer of the diffusion zone is given depending on the oxygen concentration and the duration of treatment. And also the dependences of the kinetics of displacement of the boundary of the oxide-diffusion layer are given and a system of equations for calculating the ratio of the formed phase components is developed. Thanks to the proposed analytical approach, it will be possible to calculate the sizes of interphase boundaries on the basis of temperature-time parameters and oxygen concentration and thereby form a hardened near-surface layer with certain functional properties.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80587473","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 : 2021-07-27DOI: 10.15587/2706-5448.2021.237151
S. Shlyk, Volodymyr Drahobetskyi, A. Shapoval, D. Savielov, E. Naumova, D. Bondar
The object of research is the technology of metal processing by high-speed and high-energy methods, plastic deformation of layered metal compositions. Theoretical studies are based on the main provisions of the theory of joining metals in the solid phase, the theory of plasticity, explosion welding technology, plastic deformation of layered metal compositions, and their heat treatment. The main problem of creating layered metal compositions using explosion energy, including wear and corrosion resistant, electrical, materials with high ballistic resistance, etc., is that they have not yet taken their rightful place in the range of modern structural and functional materials. This can be explained by the limited application of this process, as well as the lagging behind the theory and experimental base in the field of joining various metals in the solid phase and providing the necessary performance properties according to the needs of modern industry. The process of deformation of the cladding blank during the explosion welding is considered. The process of the workpiece collision is considered in three stages: the movement of the element of the cladding workpiece before the collision, its inertial movement and deformation. The equations of motion and equilibrium of the elements of the workpiece are described. A joint solution of the equations of plasticity and equilibrium of the blank element in the double inflection zone is presented. The work is devoted to solving the problem of increasing the level of production and economic indicators of the manufacture of layered metal compositions through the development of methods for calculating and optimizing the technological parameters. Explosion welding, as the most versatile, promising, and economical method, which still has many possibilities for the application of mathematical modeling and process optimization, has been investigated for the production and subsequent processing of the main groups of industrial metal compositions. This makes it possible to solve the problem of replacing traditional materials with layered metal compositions. The results obtained are important from the point of view of the application of cost-effective materials with high mechanical, operational, and technological properties.
{"title":"Research of the Stress-Strain State of a Workpiece Under the Double Bending by the Pulse Loading","authors":"S. Shlyk, Volodymyr Drahobetskyi, A. Shapoval, D. Savielov, E. Naumova, D. Bondar","doi":"10.15587/2706-5448.2021.237151","DOIUrl":"https://doi.org/10.15587/2706-5448.2021.237151","url":null,"abstract":"The object of research is the technology of metal processing by high-speed and high-energy methods, plastic deformation of layered metal compositions. Theoretical studies are based on the main provisions of the theory of joining metals in the solid phase, the theory of plasticity, explosion welding technology, plastic deformation of layered metal compositions, and their heat treatment. The main problem of creating layered metal compositions using explosion energy, including wear and corrosion resistant, electrical, materials with high ballistic resistance, etc., is that they have not yet taken their rightful place in the range of modern structural and functional materials. This can be explained by the limited application of this process, as well as the lagging behind the theory and experimental base in the field of joining various metals in the solid phase and providing the necessary performance properties according to the needs of modern industry. The process of deformation of the cladding blank during the explosion welding is considered. The process of the workpiece collision is considered in three stages: the movement of the element of the cladding workpiece before the collision, its inertial movement and deformation. The equations of motion and equilibrium of the elements of the workpiece are described. A joint solution of the equations of plasticity and equilibrium of the blank element in the double inflection zone is presented. The work is devoted to solving the problem of increasing the level of production and economic indicators of the manufacture of layered metal compositions through the development of methods for calculating and optimizing the technological parameters. Explosion welding, as the most versatile, promising, and economical method, which still has many possibilities for the application of mathematical modeling and process optimization, has been investigated for the production and subsequent processing of the main groups of industrial metal compositions. This makes it possible to solve the problem of replacing traditional materials with layered metal compositions. The results obtained are important from the point of view of the application of cost-effective materials with high mechanical, operational, and technological properties.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75577374","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}
Bioabsorbable metallic vascular stents (BMVSs) are an innovative technological advancement in the medical engineering field of vascular implants. BMVSs have great potential to revolutionize vascular intervention, but the lack of understanding of the construction material's natural corrosion within the body inhibits the use in clinical medicine. In this study, a corrosion function concept for in vivo implants was created to develop a multi-dimensional, non-uniform corrosion model with a larger goal of simulating the mechanical integrity of BMVSs. This proposed corrosion model simulates the corrosion rate and its effects on magnesium (Mg) alloy AZ31 based on continuum damage mechanics. The model was calibrated using three degradation experiments on Mg alloy specimens. These experiments focused on multi-dimensional corrosion, mass loss rate, and mechanical integrity during the corrosion process. Lastly, to verify the applicability of the proposed model, the resulting corrosion behaviors and mechanical characteristics of the BMVSs were implemented into a finite element framework to produce an overarching simulation of the BMVS's degradation in vivo. The results of the experiments and simulations revealed a proportional link between the corrosion of BMVSs and the number of exposed surfaces. A non-linear decline in mechanical integrity with increasing mass loss was also discovered through experimentation and modeling. Furthermore, the model and simulation can provide some details about changes in morphology and mechanics during BMVS corrosion. This work gives new insights into accurately modeling for BMVS degradation and can be used to optimize product development of BMVSs.
{"title":"A Multi-Dimensional Non-Uniform Corrosion Model for Bioabsorbable Metallic Vascular Stents","authors":"Weiliang Shi, Hongxia Li, Kellen Mitchell, Cheng Zhang, Tingzhun Zhu, Yifei Jin, Danyang Zhao","doi":"10.2139/ssrn.3743219","DOIUrl":"https://doi.org/10.2139/ssrn.3743219","url":null,"abstract":"Bioabsorbable metallic vascular stents (BMVSs) are an innovative technological advancement in the medical engineering field of vascular implants. BMVSs have great potential to revolutionize vascular intervention, but the lack of understanding of the construction material's natural corrosion within the body inhibits the use in clinical medicine. In this study, a corrosion function concept for in vivo implants was created to develop a multi-dimensional, non-uniform corrosion model with a larger goal of simulating the mechanical integrity of BMVSs. This proposed corrosion model simulates the corrosion rate and its effects on magnesium (Mg) alloy AZ31 based on continuum damage mechanics. The model was calibrated using three degradation experiments on Mg alloy specimens. These experiments focused on multi-dimensional corrosion, mass loss rate, and mechanical integrity during the corrosion process. Lastly, to verify the applicability of the proposed model, the resulting corrosion behaviors and mechanical characteristics of the BMVSs were implemented into a finite element framework to produce an overarching simulation of the BMVS's degradation in vivo. The results of the experiments and simulations revealed a proportional link between the corrosion of BMVSs and the number of exposed surfaces. A non-linear decline in mechanical integrity with increasing mass loss was also discovered through experimentation and modeling. Furthermore, the model and simulation can provide some details about changes in morphology and mechanics during BMVS corrosion. This work gives new insights into accurately modeling for BMVS degradation and can be used to optimize product development of BMVSs.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82416181","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 : 2021-06-30DOI: 10.15587/1729-4061.2021.234783
D. Laukhin, V. Poznyakov, V. Kostin, O. Beketov, N. Rott, Y. Slupska, L. Dadiverina, O. Liubymova-Zinchenko
Welding thermomechanically-strengthened materials is accompanied with certain difficulties in terms of loss of strength characteristics in the zone of thermal influence. This issue can be resolved by using the technological welding schemes that include fusion of materials in a narrow contact area. One such technological scheme is electron beam welding, which is currently widely used to fabricate structures from refractory and chemically active materials. One of the main advantages of the electron beam welding process is a small quantity of heat input, which leads to the formation of narrow zones of melting and thermal influence and, as a result, minor deformities in the structure of the material. The welded joint can structurally be divided into several zones, which differ in the morphological characteristics of the structure. The most interesting, in terms of ensuring the quality of the joint, are the boundaries between the zones. It has been shown that the use of local heating sources, which is the case at electron beam welding, leads to the migration of the boundaries of grains. As a result, clear intersections, fusion lines, form at the boundaries between zones of the welded joint. The formation of the structural state of a welded joint is predetermined by the simultaneous course of several processes. First, a crystallization from the liquid state – the formation of a welded joint structure, as well as the boundary between a welded joint and the zone of thermal influence. Second, the phase-structural transformations in the solid state – a thermal impact zone, the boundary between a thermal impact zone and the main metal. Given this, one should note that the geometry and quality of joints at electron beam welding are more interrelated than in other welding techniques. Thus, one of the main parameters that ensure the quality of a welded joint is the structural state of the material that forms during welding.
{"title":"Features in the Formation of the Structural State of Low-Carbon Micro-Alloyed Steels after Eletron Beam Welding","authors":"D. Laukhin, V. Poznyakov, V. Kostin, O. Beketov, N. Rott, Y. Slupska, L. Dadiverina, O. Liubymova-Zinchenko","doi":"10.15587/1729-4061.2021.234783","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.234783","url":null,"abstract":"Welding thermomechanically-strengthened materials is accompanied with certain difficulties in terms of loss of strength characteristics in the zone of thermal influence. This issue can be resolved by using the technological welding schemes that include fusion of materials in a narrow contact area. One such technological scheme is electron beam welding, which is currently widely used to fabricate structures from refractory and chemically active materials. One of the main advantages of the electron beam welding process is a small quantity of heat input, which leads to the formation of narrow zones of melting and thermal influence and, as a result, minor deformities in the structure of the material. The welded joint can structurally be divided into several zones, which differ in the morphological characteristics of the structure. The most interesting, in terms of ensuring the quality of the joint, are the boundaries between the zones. It has been shown that the use of local heating sources, which is the case at electron beam welding, leads to the migration of the boundaries of grains. As a result, clear intersections, fusion lines, form at the boundaries between zones of the welded joint. The formation of the structural state of a welded joint is predetermined by the simultaneous course of several processes. First, a crystallization from the liquid state – the formation of a welded joint structure, as well as the boundary between a welded joint and the zone of thermal influence. Second, the phase-structural transformations in the solid state – a thermal impact zone, the boundary between a thermal impact zone and the main metal. Given this, one should note that the geometry and quality of joints at electron beam welding are more interrelated than in other welding techniques. Thus, one of the main parameters that ensure the quality of a welded joint is the structural state of the material that forms during welding.","PeriodicalId":18268,"journal":{"name":"Materials Engineering eJournal","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82543990","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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