Pub Date : 1900-01-01DOI: 10.18323/2782-4039-2023-1-45-55
E. Merson, V. Poluyanov, P. Myagkikh, D. Merson
According to the stable opinion, hydrogen absorbed by magnesium alloys during corrosion can cause their stress corrosion cracking. One of the characteristic markers indicating the involvement of diffusible hydrogen into the fracture mechanism of metals is the negative strain rate dependence of the embrittlement degree. Recent studies show that the loss of ductility of the ZK60 alloy specimens subjected to a short-term (1.5 h) pre-exposure in a corrosive medium actually decreases with the increasing strain rate. However, after the removal of corrosion products from the surface of specimens, the strain rate dependence of the ductility loss becomes positive, which indicates the absence of hydrogen in the bulk of a metal. At a short-term exposure in a corrosive environment, the deep penetration of hydrogen into a metal could be limited due to the insufficient time for hydrogen diffusion. The paper studies the mechanical behavior of the ZK60 alloy subjected to a longer (12 h) pre-exposure in a corrosive medium followed by tensile testing in air at various strain rates. The authors consider the effect of strain rate, long-term pre-exposure in a corrosive medium, and subsequent removal of corrosion products on the strength, ductility, stages of work hardening, and localized deformation, as well as on the state of the side and fracture surfaces of specimens. The study identified that the ductility loss of specimens pre-exposed in a corrosive medium for 12 h decreases with the increasing strain rate, regardless of whether the corrosion products have been removed from their surface or not. It is shown that in this case, the negative strain rate dependence of the ductility loss is associated not with hydrogen dissolved in the bulk of a metal but with the presence of severe corrosion damage of the specimens’ surface. The authors proposed an explanation for the effect of corrosion damage on the mechanical properties and their strain rate sensitivity.
{"title":"Strain rate sensitivity of mechanical properties of the ZK60 alloy with the high degree of corrosion damage","authors":"E. Merson, V. Poluyanov, P. Myagkikh, D. Merson","doi":"10.18323/2782-4039-2023-1-45-55","DOIUrl":"https://doi.org/10.18323/2782-4039-2023-1-45-55","url":null,"abstract":"According to the stable opinion, hydrogen absorbed by magnesium alloys during corrosion can cause their stress corrosion cracking. One of the characteristic markers indicating the involvement of diffusible hydrogen into the fracture mechanism of metals is the negative strain rate dependence of the embrittlement degree. Recent studies show that the loss of ductility of the ZK60 alloy specimens subjected to a short-term (1.5 h) pre-exposure in a corrosive medium actually decreases with the increasing strain rate. However, after the removal of corrosion products from the surface of specimens, the strain rate dependence of the ductility loss becomes positive, which indicates the absence of hydrogen in the bulk of a metal. At a short-term exposure in a corrosive environment, the deep penetration of hydrogen into a metal could be limited due to the insufficient time for hydrogen diffusion. The paper studies the mechanical behavior of the ZK60 alloy subjected to a longer (12 h) pre-exposure in a corrosive medium followed by tensile testing in air at various strain rates. The authors consider the effect of strain rate, long-term pre-exposure in a corrosive medium, and subsequent removal of corrosion products on the strength, ductility, stages of work hardening, and localized deformation, as well as on the state of the side and fracture surfaces of specimens. The study identified that the ductility loss of specimens pre-exposed in a corrosive medium for 12 h decreases with the increasing strain rate, regardless of whether the corrosion products have been removed from their surface or not. It is shown that in this case, the negative strain rate dependence of the ductility loss is associated not with hydrogen dissolved in the bulk of a metal but with the presence of severe corrosion damage of the specimens’ surface. The authors proposed an explanation for the effect of corrosion damage on the mechanical properties and their strain rate sensitivity.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"151 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127562118","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 : 1900-01-01DOI: 10.18323/2782-4039-2022-2-113-120
Yu. A. Shlyarova, D. Zagulyaev, V. Gromov
The paper presents the comparative analysis of the structure and mechanical properties (microhardness) of the surface layers of the hypoeutectic Al–11Si alloy and hypereutectic Al–20Si alloy exposed to electroexplosive alloying (treatment mode: aluminum foil mass is 58.9 mg; Y2O3 powder mass is 88.3 mg; the discharge voltage is 2.6 kV). During the research, the authors identified that the Al–11Si alloy initial structure mainly consists of the Al solid solution grains. Eutectic grains are located along the grain boundaries and at the joints of aluminum grain boundaries. In the Al–11Si alloy, the aluminum grain size varies from 25 μm to 100 μm, and the Al–Si eutectic grain size varies within 10–30 μm. The hypereutectic composition Al–20Si alloy in the initial state is characterized by the presence of primary silicon inclusions predominantly of a plate-like shape. The sizes of these inclusions reach 120 μm. After electroexplosive alloying, in the Al–11Si alloy, the author identified the formation of a multilayer structure consisting of a highly-porous coating irregular in thickness, a liquid-phase alloying layer, and a heat-affected layer. The modified layer thickness for the Al–11Si alloy varies in the range of 33–60 μm, and for the Al–20Si alloy, the modified layer thickness varies within 20–100 μm. The microhardness value of the initial hypoeutectic Al–11Si alloy was 64 HV 0.05, for the hypereutectic Al–20Si alloy – 71 HV 0.05. It can be noted that the microhardness of the Al–11Si alloy surface layer exceeds the initial material microhardness more than 2.5 times. In the Al–20Si alloy, the surface layer microhardness exceeds the one of the initial material more than twice. With the increase of the distance from the modification surface, the microhardness decreases and reaches the initial alloy value at the depth of ≈90 μm.
{"title":"The comparative analysis of change in the structure and properties of Al–Si system alloys exposed to electroexplosive alloying","authors":"Yu. A. Shlyarova, D. Zagulyaev, V. Gromov","doi":"10.18323/2782-4039-2022-2-113-120","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-2-113-120","url":null,"abstract":"The paper presents the comparative analysis of the structure and mechanical properties (microhardness) of the surface layers of the hypoeutectic Al–11Si alloy and hypereutectic Al–20Si alloy exposed to electroexplosive alloying (treatment mode: aluminum foil mass is 58.9 mg; Y2O3 powder mass is 88.3 mg; the discharge voltage is 2.6 kV). During the research, the authors identified that the Al–11Si alloy initial structure mainly consists of the Al solid solution grains. Eutectic grains are located along the grain boundaries and at the joints of aluminum grain boundaries. In the Al–11Si alloy, the aluminum grain size varies from 25 μm to 100 μm, and the Al–Si eutectic grain size varies within 10–30 μm. The hypereutectic composition Al–20Si alloy in the initial state is characterized by the presence of primary silicon inclusions predominantly of a plate-like shape. The sizes of these inclusions reach 120 μm. After electroexplosive alloying, in the Al–11Si alloy, the author identified the formation of a multilayer structure consisting of a highly-porous coating irregular in thickness, a liquid-phase alloying layer, and a heat-affected layer. The modified layer thickness for the Al–11Si alloy varies in the range of 33–60 μm, and for the Al–20Si alloy, the modified layer thickness varies within 20–100 μm. The microhardness value of the initial hypoeutectic Al–11Si alloy was 64 HV 0.05, for the hypereutectic Al–20Si alloy – 71 HV 0.05. It can be noted that the microhardness of the Al–11Si alloy surface layer exceeds the initial material microhardness more than 2.5 times. In the Al–20Si alloy, the surface layer microhardness exceeds the one of the initial material more than twice. With the increase of the distance from the modification surface, the microhardness decreases and reaches the initial alloy value at the depth of ≈90 μm.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127829174","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 : 1900-01-01DOI: 10.18323/2782-4039-2022-4-30-37
D. Gunderov, A. G. Stotsky, V. Aubakirova, S. Gunderova, Y. Lebedev
High-pressure torsion deformation (HPT) is an effective method for transforming the structure of metallic materials, forming a nanostructural state in them, and significantly improving their strength. However, deformation achieved during HPT can be much less than expected due to the slippage. The study of the slippage effect during HPT of various materials is a topical issue. Previously, the authors proposed a simple and illustrative method for assessing slippage and the actual degree of torsion deformation achieved during HPT. Zr–1%Nb alloys, on which many studies of the HPT effect previously have been carried out, are good material for studying the slippage effect during HPT. Therefore, it is possible to compare obtained data with the results of other authors. The paper investigates the HPT impact on the structure and properties of the Zr–1%Nb alloy and demonstrates the slippage effect. The initial disk, prepared for HPT, was cut into two half-disks that were jointly placed on the strikers and exposed to joint HPT for n=¼ revolutions of anvils. The authors evaluated the slippage effect from the view of halves. The study showed that even at the initial HPT stages at n=¼ revolutions, there is a significant slippage of strikers and a sample, and the torsion deformation does not accumulate as expected. The authors analyzed the influence of various HPT modes on the microhardness, structure, and phase composition of the Zr–1%Nb alloy. The study shows that, despite the slippage effect, the Zr–1%Nb alloy is strongly hardened during HPT for one revolution (n=1) and HPT with n=10; the microhardness and tensile strength increase significantly, and up to 90 % of high-pressure ω-phases is formed in the sample. The authors conclude that during HPT, the deformation is implemented not by simple torsion but by the more complex modes.
{"title":"The investigation of the slippage effect, transformation of the structure and properties of the Zr–1%Nb alloy during high-pressure torsion deformation","authors":"D. Gunderov, A. G. Stotsky, V. Aubakirova, S. Gunderova, Y. Lebedev","doi":"10.18323/2782-4039-2022-4-30-37","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-4-30-37","url":null,"abstract":"High-pressure torsion deformation (HPT) is an effective method for transforming the structure of metallic materials, forming a nanostructural state in them, and significantly improving their strength. However, deformation achieved during HPT can be much less than expected due to the slippage. The study of the slippage effect during HPT of various materials is a topical issue. Previously, the authors proposed a simple and illustrative method for assessing slippage and the actual degree of torsion deformation achieved during HPT. Zr–1%Nb alloys, on which many studies of the HPT effect previously have been carried out, are good material for studying the slippage effect during HPT. Therefore, it is possible to compare obtained data with the results of other authors. The paper investigates the HPT impact on the structure and properties of the Zr–1%Nb alloy and demonstrates the slippage effect. The initial disk, prepared for HPT, was cut into two half-disks that were jointly placed on the strikers and exposed to joint HPT for n=¼ revolutions of anvils. The authors evaluated the slippage effect from the view of halves. The study showed that even at the initial HPT stages at n=¼ revolutions, there is a significant slippage of strikers and a sample, and the torsion deformation does not accumulate as expected. The authors analyzed the influence of various HPT modes on the microhardness, structure, and phase composition of the Zr–1%Nb alloy. The study shows that, despite the slippage effect, the Zr–1%Nb alloy is strongly hardened during HPT for one revolution (n=1) and HPT with n=10; the microhardness and tensile strength increase significantly, and up to 90 % of high-pressure ω-phases is formed in the sample. The authors conclude that during HPT, the deformation is implemented not by simple torsion but by the more complex modes.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134058158","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 : 1900-01-01DOI: 10.18323/2782-4039-2023-2-64-4
A. Y. Plesovskikh, S. Krylova
The paper presents the results of reverse engineering including metallographic, mechanical, and engineering-technical studies of used rods of a compressor produced by the Dresser-Rand company (Siemens, Germany). The study established that the original product is made of AISI 4140 steel with a working coating based on tungsten carbide applied to a depth of 0.2 mm by the HVOF method. The paper contains the results of the development of an import-substituting technological process for producing a wear-resistant powder coating of the Ni–Cr–B–WC system applied by cold gas flame spraying on the surface of a critical unit of compressor equipment in the oil and gas industry. Microanalysis identified that the sprayed spherical WC particles are evenly distributed in the nickel bond without the formation of free cavities at the lamella boundary, retain the size identical to the original powder composition upon the high-speed collision with the substrate, and minimize the level of residual mechanical stresses in the surface layer. The study shows that the sprayed coating has a high microhardness (the bases – 700 HV0.1, WC – up to 2000 HV0.1), which ensures high wear resistance during operation of the rod in a friction pair. A comparative analysis of the tribological properties of the coatings showed that when changing the shape, particle size distribution, and percentage ratio of tungsten carbide from 20 to 70 % in the nickel matrix, the overall wear resistance of the coating equivalently increases. The authors concluded on the possibility of manufacturing an import-substituting product using the gas flame spraying technology with metallurgical powder compositions containing tungsten. The authors developed an industrial technology for applying a wear-resistant coating on the working surface of a rod made of AISI 4140 steel. The paper presents the results of the analysis of the stress state of a material with a coating produced using the developed technology in comparison with the original product. In the product obtained by the experimental technology, in the process of applying the coating and its subsequent mechanical processing, uniform residual mechanical stresses are formed that do not exceed the value of the difference in the principal mechanical stresses. The paper presents the results of the study obtained both on standard samples and on a pilot part.
{"title":"The study of the structure and properties of a wear-resistant gas-thermal coating containing tungsten","authors":"A. Y. Plesovskikh, S. Krylova","doi":"10.18323/2782-4039-2023-2-64-4","DOIUrl":"https://doi.org/10.18323/2782-4039-2023-2-64-4","url":null,"abstract":"The paper presents the results of reverse engineering including metallographic, mechanical, and engineering-technical studies of used rods of a compressor produced by the Dresser-Rand company (Siemens, Germany). The study established that the original product is made of AISI 4140 steel with a working coating based on tungsten carbide applied to a depth of 0.2 mm by the HVOF method. The paper contains the results of the development of an import-substituting technological process for producing a wear-resistant powder coating of the Ni–Cr–B–WC system applied by cold gas flame spraying on the surface of a critical unit of compressor equipment in the oil and gas industry. Microanalysis identified that the sprayed spherical WC particles are evenly distributed in the nickel bond without the formation of free cavities at the lamella boundary, retain the size identical to the original powder composition upon the high-speed collision with the substrate, and minimize the level of residual mechanical stresses in the surface layer. The study shows that the sprayed coating has a high microhardness (the bases – 700 HV0.1, WC – up to 2000 HV0.1), which ensures high wear resistance during operation of the rod in a friction pair. A comparative analysis of the tribological properties of the coatings showed that when changing the shape, particle size distribution, and percentage ratio of tungsten carbide from 20 to 70 % in the nickel matrix, the overall wear resistance of the coating equivalently increases. The authors concluded on the possibility of manufacturing an import-substituting product using the gas flame spraying technology with metallurgical powder compositions containing tungsten. The authors developed an industrial technology for applying a wear-resistant coating on the working surface of a rod made of AISI 4140 steel. The paper presents the results of the analysis of the stress state of a material with a coating produced using the developed technology in comparison with the original product. In the product obtained by the experimental technology, in the process of applying the coating and its subsequent mechanical processing, uniform residual mechanical stresses are formed that do not exceed the value of the difference in the principal mechanical stresses. The paper presents the results of the study obtained both on standard samples and on a pilot part.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114630883","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 : 1900-01-01DOI: 10.18323/2782-4039-2022-1-73-81
T. R. Suaridze, Yulia V. Khlebnikova, L. Egorova
After cold-rolling reduction with the shrinkage of more than 97 % and recrystallization annealing, the edged cubic texture develops in some fcc lattice metals with the high and medium values of stacking fault energy such as Ni, Cu, Al, Pt, and some alloys on their base. The extended bands of metals and fcc lattice alloys can be used to apply multilayer functional compositions. The authors studied the structure and crystallographic texture in bands of three-component copper-nickel-based alloys. The study showed the crucial possibility of creating multi-component alloys based on the Cu+40% Ni binary alloy doped with such elements as Mo or Nb. The paper considers the formation of an edged cubic texture in bands of Cu–Ni–Mn, Cu–Ni–Nb, and Cu–Ni–Мо alloys produced through cold deformation with rolling and recrystallization annealing performed at different temperatures. The study identified that annealing during one hour at 1050 °С was an optimal recrystallization annealing mode when on the surface of bands made of (Cu+40 % Ni)–Me alloys (where Me=Mn, Mo, Nb) deformed at ~99 %, the most perfect cubic texture was realized. According to the data obtained, after such annealing mode, from 94% to 98% of grains with orientation {001}<100> developed in the Cu–40% Ni–1.3% Mn, Cu–40% Ni–0.8% Mo, and Cu–40% Ni–0.5% Nb alloys. It opens the prospect of using these alloys as epitaxial substrates in the technology of high-temperature second-generation superconductors. The evaluation of mechanical characteristics showed that alloying contributed to an increase in the yield strength of Cu–40% Ni–1.3% Mn, Cu–40% Ni–0.8% Mo, and Cu–40% Ni–0.5% Nb alloys by 3–4 times compared with the yield strength value of a textured copper band.
{"title":"FORMING AN EDGED CUBIC TEXTURE IN BAND SUBSTRATES MADE OF (Cu+Ni)–Me (Me=Mo, Mn, Nb) ALLOYS FOR HIGH-TEMPERATURE SECOND-GENERATION SUPERCONDUCTORS","authors":"T. R. Suaridze, Yulia V. Khlebnikova, L. Egorova","doi":"10.18323/2782-4039-2022-1-73-81","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-1-73-81","url":null,"abstract":"After cold-rolling reduction with the shrinkage of more than 97 % and recrystallization annealing, the edged cubic texture develops in some fcc lattice metals with the high and medium values of stacking fault energy such as Ni, Cu, Al, Pt, and some alloys on their base. The extended bands of metals and fcc lattice alloys can be used to apply multilayer functional compositions. The authors studied the structure and crystallographic texture in bands of three-component copper-nickel-based alloys. The study showed the crucial possibility of creating multi-component alloys based on the Cu+40% Ni binary alloy doped with such elements as Mo or Nb. The paper considers the formation of an edged cubic texture in bands of Cu–Ni–Mn, Cu–Ni–Nb, and Cu–Ni–Мо alloys produced through cold deformation with rolling and recrystallization annealing performed at different temperatures. The study identified that annealing during one hour at 1050 °С was an optimal recrystallization annealing mode when on the surface of bands made of (Cu+40 % Ni)–Me alloys (where Me=Mn, Mo, Nb) deformed at ~99 %, the most perfect cubic texture was realized. According to the data obtained, after such annealing mode, from 94% to 98% of grains with orientation {001}<100> developed in the Cu–40% Ni–1.3% Mn, Cu–40% Ni–0.8% Mo, and Cu–40% Ni–0.5% Nb alloys. It opens the prospect of using these alloys as epitaxial substrates in the technology of high-temperature second-generation superconductors. The evaluation of mechanical characteristics showed that alloying contributed to an increase in the yield strength of Cu–40% Ni–1.3% Mn, Cu–40% Ni–0.8% Mo, and Cu–40% Ni–0.5% Nb alloys by 3–4 times compared with the yield strength value of a textured copper band.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114816542","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 : 1900-01-01DOI: 10.18323/2782-4039-2022-3-1-33-40
V. Astanin, D. Gunderov, V. V. Titov
Identifying the peculiarities of the transformation of the structure and properties of bulk metallic glass (BMG) under high-pressure torsion (HPT) is of great interest. It is known that under HPT, the degree of deformation differs from the center to the edge of a disk which leads to the non-uniformity of the structure of obtained specimens. The change in microhardness value indicates the direction of change in BMG structure under the HPT, and the microhardness distribution indicates the HPT-specimen non-uniformity. The aim of the study is to identify the HPT influence on the microhardness value and microhardness distribution over the surface of specimens of amorphous alloys using an example of Vit105Zr-based BMG (Zr52.5Cu17.9Ni14.6Al10Ti5). The authors studied the distribution of microhardness over the surface of Vit105 Zr-based bulk metallic glass (BMG) in the initial state, in the state after HPT at n=1 and n=5 rotations, and after relaxing annealing. The study shows that the initial Vit105 BMG is characterized by a small spread in microhardness values, which indicates the material's high homogeneity. By reducing the excessive free volume, relaxing annealing increases microhardness without a significant increase in the spread of its values. HPT leads to a decrease in the zirconium BMG microhardness, which indicates an increase in the excessive free volume, but, at the same time, increases the uneven microhardness distribution over the specimen, while the microhardness values in one half of the HPT sample (n=1) are higher than in the other one. It demonstrates that BMG specimen deformation during HPT is related to the specific loading mechanisms.
{"title":"Microhardness distribution over the surface of Zr-based metallic glass exposed to high-pressure torsion","authors":"V. Astanin, D. Gunderov, V. V. Titov","doi":"10.18323/2782-4039-2022-3-1-33-40","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-3-1-33-40","url":null,"abstract":"Identifying the peculiarities of the transformation of the structure and properties of bulk metallic glass (BMG) under high-pressure torsion (HPT) is of great interest. It is known that under HPT, the degree of deformation differs from the center to the edge of a disk which leads to the non-uniformity of the structure of obtained specimens. The change in microhardness value indicates the direction of change in BMG structure under the HPT, and the microhardness distribution indicates the HPT-specimen non-uniformity. The aim of the study is to identify the HPT influence on the microhardness value and microhardness distribution over the surface of specimens of amorphous alloys using an example of Vit105Zr-based BMG (Zr52.5Cu17.9Ni14.6Al10Ti5). The authors studied the distribution of microhardness over the surface of Vit105 Zr-based bulk metallic glass (BMG) in the initial state, in the state after HPT at n=1 and n=5 rotations, and after relaxing annealing. The study shows that the initial Vit105 BMG is characterized by a small spread in microhardness values, which indicates the material's high homogeneity. By reducing the excessive free volume, relaxing annealing increases microhardness without a significant increase in the spread of its values. HPT leads to a decrease in the zirconium BMG microhardness, which indicates an increase in the excessive free volume, but, at the same time, increases the uneven microhardness distribution over the specimen, while the microhardness values in one half of the HPT sample (n=1) are higher than in the other one. It demonstrates that BMG specimen deformation during HPT is related to the specific loading mechanisms.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123694422","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 : 1900-01-01DOI: 10.18323/2782-4039-2022-4-18-29
A. A. Afanaseva, O. Bashkov, V. S. Fadeev
The continuous increase in the speed and load of railway transport operating in a wide range of climatic zones of the Russian Federation creates a need to develop new friction materials with the improved performance properties that can ensure high functioning reliability of the electric switch mechanisms. The paper presents the results of the study of the microstructure, physical, mechanical, and operational properties of a new material for friction inserts based on an iron matrix for the switch gear clutches. The new material composition includes such components as Fe, Cu, BaSO4, SiO2, C, and Zn. The authors propose a technique for selecting materials with the specified performance properties based on the results of the research carried out using the experiment factorial planning. For this purpose, the authors carried out the studies and established a relationship between the values of microstructure indicators, physical, mechanical and operational properties of the materials with different quantitative composition of components. The grain boundary density was proposed as an indicator of the dissipative properties of the material, and the possibility of its application as a structural parameter for evaluating the friction material performance characteristics. To assess the friction material performance characteristics, which determine the possibility of its application as a part of the friction clutches of the electric switch mechanism, the authors proposed a new parameter – the endurance period . Another service property was the deviation of the friction coefficient ƒ values in the range of values of the clamping force of the electric switch mechanism. According to the results of bench tests of a new friction material within the friction clutches of the electric switch mechanism, the authors identified a high wear resistance of the material and the possibility of its use in severe climatic conditions. The proposed testing technique allows predicting the performance properties of new materials at the stage of studying the microstructure based on the obtained dependences, which can significantly narrow the search range.
{"title":"The study of the structure and properties of a friction composite material based on an iron matrix","authors":"A. A. Afanaseva, O. Bashkov, V. S. Fadeev","doi":"10.18323/2782-4039-2022-4-18-29","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-4-18-29","url":null,"abstract":"The continuous increase in the speed and load of railway transport operating in a wide range of climatic zones of the Russian Federation creates a need to develop new friction materials with the improved performance properties that can ensure high functioning reliability of the electric switch mechanisms. The paper presents the results of the study of the microstructure, physical, mechanical, and operational properties of a new material for friction inserts based on an iron matrix for the switch gear clutches. The new material composition includes such components as Fe, Cu, BaSO4, SiO2, C, and Zn. The authors propose a technique for selecting materials with the specified performance properties based on the results of the research carried out using the experiment factorial planning. For this purpose, the authors carried out the studies and established a relationship between the values of microstructure indicators, physical, mechanical and operational properties of the materials with different quantitative composition of components. The grain boundary density was proposed as an indicator of the dissipative properties of the material, and the possibility of its application as a structural parameter for evaluating the friction material performance characteristics. To assess the friction material performance characteristics, which determine the possibility of its application as a part of the friction clutches of the electric switch mechanism, the authors proposed a new parameter – the endurance period . Another service property was the deviation of the friction coefficient ƒ values in the range of values of the clamping force of the electric switch mechanism. According to the results of bench tests of a new friction material within the friction clutches of the electric switch mechanism, the authors identified a high wear resistance of the material and the possibility of its use in severe climatic conditions. The proposed testing technique allows predicting the performance properties of new materials at the stage of studying the microstructure based on the obtained dependences, which can significantly narrow the search range.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114975637","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 : 1900-01-01DOI: 10.18323/2782-4039-2023-1-57-67
Мурашкин Сергей Викторович, Селиванов Александр Сергеевич, Спиридонов Николай Германович, Савина Елена Борисовна
Polypropylene is one of the most popular thermoplastic materials used in industry. To produce goods from this material, the ultrasonic welding method is often used. However, despite a large number of scientific papers, the influence of some parameters of the ultrasonic welding mode on the strength characteristics of polypropylene joints remains unstudied. The paper presents the results of experimental studies of contact spot ultrasonic welding of plates 3 mm thick made of 01003-26 grade polypropylene. The authors considered the process of gradual penetration of the ultrasonic tool working face into polypropylene to a depth equal to the total thickness of the welded plates. Statistical dependences of the depth of the tool face penetration into the material and the force of material separation on the ultrasound exposure time are obtained. The influence of the depth of the ultrasonic tool working face penetration on the tearing force of welded specimens is determined. A significant increase in the tearing force from 150 to 400 N was found at the tool penetration depth of more than 3.5 mm due to an increase in the nominal area of mutual mixing of the material between the welded plates caused by the flow of molten material into the gap. The authors proposed a hypothesis about the flow of the molten material in the direction opposite to the direction of penetration of the working tool by forming traveling Rayleigh waves. However, its confirmation requires additional studies of the influence of the ultrasonic welding mode parameters and the size of the gap between the parts to be joined on the rate of the molten material flow into the gap.
{"title":"Statistical dependences of influence of ultrasonic exposure time on the strength and other parameters of a polypropylene welded joint","authors":"Мурашкин Сергей Викторович, Селиванов Александр Сергеевич, Спиридонов Николай Германович, Савина Елена Борисовна","doi":"10.18323/2782-4039-2023-1-57-67","DOIUrl":"https://doi.org/10.18323/2782-4039-2023-1-57-67","url":null,"abstract":"Polypropylene is one of the most popular thermoplastic materials used in industry. To produce goods from this material, the ultrasonic welding method is often used. However, despite a large number of scientific papers, the influence of some parameters of the ultrasonic welding mode on the strength characteristics of polypropylene joints remains unstudied. The paper presents the results of experimental studies of contact spot ultrasonic welding of plates 3 mm thick made of 01003-26 grade polypropylene. The authors considered the process of gradual penetration of the ultrasonic tool working face into polypropylene to a depth equal to the total thickness of the welded plates. Statistical dependences of the depth of the tool face penetration into the material and the force of material separation on the ultrasound exposure time are obtained. The influence of the depth of the ultrasonic tool working face penetration on the tearing force of welded specimens is determined. A significant increase in the tearing force from 150 to 400 N was found at the tool penetration depth of more than 3.5 mm due to an increase in the nominal area of mutual mixing of the material between the welded plates caused by the flow of molten material into the gap. The authors proposed a hypothesis about the flow of the molten material in the direction opposite to the direction of penetration of the working tool by forming traveling Rayleigh waves. However, its confirmation requires additional studies of the influence of the ultrasonic welding mode parameters and the size of the gap between the parts to be joined on the rate of the molten material flow into the gap.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123901854","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 : 1900-01-01DOI: 10.18323/2782-4039-2022-1-82-90
I. Tumbusova, G. Maier
Complex solid solution hardening of austenitic chrome-manganese steels by nitrogen and carbon is one of the most effective ways of production of high-nitrogen austenitic steels (HNS) without using special casting methods. To enhance the solubility of interstitials in the metal liquid state and suppress undesired secondary phases of Cr2N and Cr23C6, the carbide-forming elements (for instance, vanadium) are added to the HNS composition. By now, there are no experimental works on the age-hardening of ultrahigh-interstitial vanadium steels (more than 1 % wt.). In the present work, the authors used the X-ray structure analysis method, electron microscopy, and the uniaxial static tensile tests to study the effect of temperature (600 °С and 700 °С) and duration (0.5 h, 5 h) of age-hardening on the structure and mechanical properties of ultrahigh-interstitial vanadium-containing Cr–Mn steel (Fe–22Cr–26Mn–1.3V–0.7C–1.2N, N+C=1.9 % wt.). The experiments demonstrated that due to the complex decomposition (by intermittent and continuous mechanisms) of austenite saturated by interstitials, the aging at 600 °С and 700 °С is accompanied by a solid-solution hardening of the austenitic phase by carbonitrides Cr2(N, С) and (V,Cr)(N,С). The study identified that the increased temperature and prolongation of age-hardening stimulate the movement of intermittent decomposition front from the boundaries to the center of austenitic grains. (V,Cr)(N,С) particles formed by the continuous decomposition in the austenitic grains hinder the propagation of the reaction front, meanwhile, the large spherical (V,Cr)(N,C) and Cr2(N,C) particles, not dissolved after quenching, have little effect on its movement. At the chosen age-hardening modes, the yield strength of steel increases, and the fracture elongation decreases.
{"title":"THE INFLUENCE OF AGING ON PHASE COMPOSITION AND MECHANICAL PROPERTIES OF VANADIUM-ALLOYED HIGH-NITROGEN STEEL","authors":"I. Tumbusova, G. Maier","doi":"10.18323/2782-4039-2022-1-82-90","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-1-82-90","url":null,"abstract":"Complex solid solution hardening of austenitic chrome-manganese steels by nitrogen and carbon is one of the most effective ways of production of high-nitrogen austenitic steels (HNS) without using special casting methods. To enhance the solubility of interstitials in the metal liquid state and suppress undesired secondary phases of Cr2N and Cr23C6, the carbide-forming elements (for instance, vanadium) are added to the HNS composition. By now, there are no experimental works on the age-hardening of ultrahigh-interstitial vanadium steels (more than 1 % wt.). In the present work, the authors used the X-ray structure analysis method, electron microscopy, and the uniaxial static tensile tests to study the effect of temperature (600 °С and 700 °С) and duration (0.5 h, 5 h) of age-hardening on the structure and mechanical properties of ultrahigh-interstitial vanadium-containing Cr–Mn steel (Fe–22Cr–26Mn–1.3V–0.7C–1.2N, N+C=1.9 % wt.). The experiments demonstrated that due to the complex decomposition (by intermittent and continuous mechanisms) of austenite saturated by interstitials, the aging at 600 °С and 700 °С is accompanied by a solid-solution hardening of the austenitic phase by carbonitrides Cr2(N, С) and (V,Cr)(N,С). The study identified that the increased temperature and prolongation of age-hardening stimulate the movement of intermittent decomposition front from the boundaries to the center of austenitic grains. (V,Cr)(N,С) particles formed by the continuous decomposition in the austenitic grains hinder the propagation of the reaction front, meanwhile, the large spherical (V,Cr)(N,C) and Cr2(N,C) particles, not dissolved after quenching, have little effect on its movement. At the chosen age-hardening modes, the yield strength of steel increases, and the fracture elongation decreases.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129515095","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 : 1900-01-01DOI: 10.18323/2782-4039-2022-4-90-101
Y. Nikitin
To ensure the quality of applying anti-corrosion insulation of welded joints inside pipelines with the internal protective coating, it is necessary to keep temperature regimes of a welded joint specified heating zone with high accuracy, including the heating rate and keeping the heating temperature of anti-corrosion insulation for a certain time. Nowadays, the industry does not produce compact and easy-to-use devices for heating welded joints of small-diameter pipelines when applying internal insulation in the field environment, so it is necessary to study the development of such types of devices and identify the efficiency of their use in practice. During the study, the author applies the induction heating method using a flexible induction heater of a pipeline welded joint. The heater is easy-to-install and ensures the required technological modes of heating the insulation inside the pipelines. The paper presents the results of modeling thermal processes, and, using the COMSOL Multiphysics package, studies temperature distribution along the joined pipelines. The study identified that due to uneven heating of a pipeline joint, temperature deviations falling outside the specified range occur. The author proposes a solution for this problem, which is a structural solution for the developed flexible inductor. The author used a specific laying of inductor winding to ensure the required heating characteristics. The experimental dependences of temperature change on the heating time inside the joined pipelines at the specified heating zones, which indicate the compliance with the requirement for the technology of insulating coating application, when entering various heating modes are obtained. The induction heater power required for heating the pipeline with a diameter of 159 mm and wall thickness of 8 mm was no more than 3 kW. The developed heaters provide the possibility of quick and convenient installation on pipelines, safety, and automation of insulation application. The study solves an important aspect of the problem of practical use of the technology of anti-corrosion protection of a welded bell-and-bell joint of pipelines of small diameters in the oil-and-gas industry.
{"title":"Development and research of a flexible induction heater of internal insulation of a welded joint of pipelines","authors":"Y. Nikitin","doi":"10.18323/2782-4039-2022-4-90-101","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-4-90-101","url":null,"abstract":"To ensure the quality of applying anti-corrosion insulation of welded joints inside pipelines with the internal protective coating, it is necessary to keep temperature regimes of a welded joint specified heating zone with high accuracy, including the heating rate and keeping the heating temperature of anti-corrosion insulation for a certain time. Nowadays, the industry does not produce compact and easy-to-use devices for heating welded joints of small-diameter pipelines when applying internal insulation in the field environment, so it is necessary to study the development of such types of devices and identify the efficiency of their use in practice. During the study, the author applies the induction heating method using a flexible induction heater of a pipeline welded joint. The heater is easy-to-install and ensures the required technological modes of heating the insulation inside the pipelines. The paper presents the results of modeling thermal processes, and, using the COMSOL Multiphysics package, studies temperature distribution along the joined pipelines. The study identified that due to uneven heating of a pipeline joint, temperature deviations falling outside the specified range occur. The author proposes a solution for this problem, which is a structural solution for the developed flexible inductor. The author used a specific laying of inductor winding to ensure the required heating characteristics. The experimental dependences of temperature change on the heating time inside the joined pipelines at the specified heating zones, which indicate the compliance with the requirement for the technology of insulating coating application, when entering various heating modes are obtained. The induction heater power required for heating the pipeline with a diameter of 159 mm and wall thickness of 8 mm was no more than 3 kW. The developed heaters provide the possibility of quick and convenient installation on pipelines, safety, and automation of insulation application. The study solves an important aspect of the problem of practical use of the technology of anti-corrosion protection of a welded bell-and-bell joint of pipelines of small diameters in the oil-and-gas industry.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130841673","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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