Pub Date : 1900-01-01DOI: 10.18323/2782-4039-2022-3-1-41-49
R. Asfandiyarov, G. Raab, D. Gunderov, D. Aksenov, A. Raab, S. Gunderova, M. A. Shishkunova
Increasing the fatigue resistance of implants is an important scientific and technical problem. One of the solutions to this problem is the high-strength state formation due to the ultrafine-grained (UFG) structure. However, high-strength alloys are characterized by greater sensitivity to stress concentrators and the surface roughness parameter. In turn, implant designs, as a rule, imply the presence of concentrators in the form of various grooves, threaded elements, etc., and the manufacturing technology supposes mechanical processing with an ambiguous effect on a finished product surface. The application of additional surface finishing, for example, abrasive-free ultrasonic finishing (AFUF), is a solution to this problem. This work aims to study the effect of different AFUF modes on the microhardness and roughness of a cylindrical blank made of Grade 4 commercially pure titanium in the UFG state. During the study, the authors assessed the effect of the rotation frequency of a workpiece and the static force of pressing the tool against the processed workpiece on the surface parameters; carried out microstructural studies of the obtained samples. The results showed that processing titanium in the UFG state by the AFUF method leads to a significant increase in the surface microhardness and a decrease in its roughness. For example, depending on the mode, the increase in microhardness can reach from 2 to 3.5 times. The authors investigated the effect of a power level of ultrasonic treatment on roughness and microhardness and considered various variants of surface pretreatment. The study identified that an increase in the speed of rotation of a workpiece reduces the roughness of a machined workpiece, while the microhardness increases.
{"title":"Roughness and microhardness of UFG Grade 4 titanium under abrasive-free ultrasonic finishing","authors":"R. Asfandiyarov, G. Raab, D. Gunderov, D. Aksenov, A. Raab, S. Gunderova, M. A. Shishkunova","doi":"10.18323/2782-4039-2022-3-1-41-49","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-3-1-41-49","url":null,"abstract":"Increasing the fatigue resistance of implants is an important scientific and technical problem. One of the solutions to this problem is the high-strength state formation due to the ultrafine-grained (UFG) structure. However, high-strength alloys are characterized by greater sensitivity to stress concentrators and the surface roughness parameter. In turn, implant designs, as a rule, imply the presence of concentrators in the form of various grooves, threaded elements, etc., and the manufacturing technology supposes mechanical processing with an ambiguous effect on a finished product surface. The application of additional surface finishing, for example, abrasive-free ultrasonic finishing (AFUF), is a solution to this problem. This work aims to study the effect of different AFUF modes on the microhardness and roughness of a cylindrical blank made of Grade 4 commercially pure titanium in the UFG state. During the study, the authors assessed the effect of the rotation frequency of a workpiece and the static force of pressing the tool against the processed workpiece on the surface parameters; carried out microstructural studies of the obtained samples. The results showed that processing titanium in the UFG state by the AFUF method leads to a significant increase in the surface microhardness and a decrease in its roughness. For example, depending on the mode, the increase in microhardness can reach from 2 to 3.5 times. The authors investigated the effect of a power level of ultrasonic treatment on roughness and microhardness and considered various variants of surface pretreatment. The study identified that an increase in the speed of rotation of a workpiece reduces the roughness of a machined workpiece, while the microhardness increases.","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":"125152464","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: 10.18323/2782-4039-2022-3-1-23-32
D. Aksenov, S. Faizova, I. Faizov
Phase transformations play an important role in the formation of properties in the dispersion-hardened alloys, for example, such as the Cu–Cr–Zr system alloys. It is known that under severe plastic deformation, the diffusion conditions change significantly, which leads to a change in the phase transformation kinetics. In this work, the authors studied the Cu–0.6Cr–0.1Zr alloy in the low concentration solid solution state subjected to high pressure torsion (up to 10 cycles). In this case, due to the solid solution low concentration and the formed ensemble of large particles, the process of solid solution decomposition was excluded at the first stages. The preliminary work on the analysis of such structurally sensitive characteristics as electrical conductivity and lattice parameter made it possible to identify the nonmonotonic nature of a change in the alloying elements concentration in the solid solution during HPT. Nonmonotonicity is related to the significant changes in the characteristics of the second phase particles ensemble under the influence of high voltages. Such significant structural changes are reflected in the nature of the mechanical characteristics change. The authors identified that when increasing the number of HPT revolutions, changes in strength also have a nonmonotonic nature, which corresponds to the nonmonotonic nature of changes in the concentration of alloying elements and electrical conductivity. Various contributions to the Cu–0.6Cr–0.1Zr alloy hardening were analyzed. The analysis identified that the dispersion strengthening contribution plays the main role in the nonmonotonic change in the mechanical characteristics. The calculated data correlate with the obtained experimental results.
{"title":"Hardening mechanisms contribution at nonmonotonic change of properties in the Cu–0.6Cr–0.1Zr alloy at high pressure torsion","authors":"D. Aksenov, S. Faizova, I. Faizov","doi":"10.18323/2782-4039-2022-3-1-23-32","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-3-1-23-32","url":null,"abstract":"Phase transformations play an important role in the formation of properties in the dispersion-hardened alloys, for example, such as the Cu–Cr–Zr system alloys. It is known that under severe plastic deformation, the diffusion conditions change significantly, which leads to a change in the phase transformation kinetics. In this work, the authors studied the Cu–0.6Cr–0.1Zr alloy in the low concentration solid solution state subjected to high pressure torsion (up to 10 cycles). In this case, due to the solid solution low concentration and the formed ensemble of large particles, the process of solid solution decomposition was excluded at the first stages. The preliminary work on the analysis of such structurally sensitive characteristics as electrical conductivity and lattice parameter made it possible to identify the nonmonotonic nature of a change in the alloying elements concentration in the solid solution during HPT. Nonmonotonicity is related to the significant changes in the characteristics of the second phase particles ensemble under the influence of high voltages. Such significant structural changes are reflected in the nature of the mechanical characteristics change. The authors identified that when increasing the number of HPT revolutions, changes in strength also have a nonmonotonic nature, which corresponds to the nonmonotonic nature of changes in the concentration of alloying elements and electrical conductivity. Various contributions to the Cu–0.6Cr–0.1Zr alloy hardening were analyzed. The analysis identified that the dispersion strengthening contribution plays the main role in the nonmonotonic change in the mechanical characteristics. The calculated data correlate with the obtained experimental results.","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":"121430456","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: 10.18323/2782-4039-2022-2-63-73
P. Myagkikh, E. Merson, V. Poluyanov, D. Merson
Biodegradable magnesium alloys are one of the most promising materials for osteosynthesis surgical implants due to the combination of unique properties: high strength, low weight, Young’s modulus close to the bone’s one, and low cytotoxicity. The most important performance characteristic is the corrosion rate, which determines the lifetime of an implant. At the moment, the main efforts of the researchers are aimed at finding a material with optimal corrosion properties ensuring the preservation of the operational properties of an implant during the bone healing period. Most of the works on this issue cover the study of the influence of the alloy chemical composition. At the same time, it is widely known that the structure of a material can also have a great effect on corrosion, for example, grain refinement can even change its type. Besides, it is important that the materials with the same quantitative parameters of corrosion can be substantially different in terms of the corrosion process staging. The authors studied the WZ31 and ZX10 magnesium alloys in two states: as-cast (coarse-grained) and after multi-axial isothermal forging and pressing (fine-grained), using the up-to-date in-situ methods that allow monitoring the dynamics of changes in the corrosion rate, as well as the staging of the corrosion damage development on the sample surface. Such methods are the corrosion rate measuring by hydrogen evolution and the sample’s surface video-monitoring during the corrosion attack. The authors carried out tests within the conditions similar to the human body conditions, such as temperature, the corrosion environment composition, and pH level. The obtained results show that the type of corrosion of the WZ31 alloy changes with the decrease in the grain size from a relatively uniform to a highly localized corrosion. In contrast, the ZX10 alloy showed a decrease in the corrosion rate with the decreasing grain size, but the corrosion type did not change.
{"title":"Structure effect on the kinetics and staging of the corrosion process of biodegradable ZX10 and WZ31 magnesium alloys","authors":"P. Myagkikh, E. Merson, V. Poluyanov, D. Merson","doi":"10.18323/2782-4039-2022-2-63-73","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-2-63-73","url":null,"abstract":"Biodegradable magnesium alloys are one of the most promising materials for osteosynthesis surgical implants due to the combination of unique properties: high strength, low weight, Young’s modulus close to the bone’s one, and low cytotoxicity. The most important performance characteristic is the corrosion rate, which determines the lifetime of an implant. At the moment, the main efforts of the researchers are aimed at finding a material with optimal corrosion properties ensuring the preservation of the operational properties of an implant during the bone healing period. Most of the works on this issue cover the study of the influence of the alloy chemical composition. At the same time, it is widely known that the structure of a material can also have a great effect on corrosion, for example, grain refinement can even change its type. Besides, it is important that the materials with the same quantitative parameters of corrosion can be substantially different in terms of the corrosion process staging. The authors studied the WZ31 and ZX10 magnesium alloys in two states: as-cast (coarse-grained) and after multi-axial isothermal forging and pressing (fine-grained), using the up-to-date in-situ methods that allow monitoring the dynamics of changes in the corrosion rate, as well as the staging of the corrosion damage development on the sample surface. Such methods are the corrosion rate measuring by hydrogen evolution and the sample’s surface video-monitoring during the corrosion attack. The authors carried out tests within the conditions similar to the human body conditions, such as temperature, the corrosion environment composition, and pH level. The obtained results show that the type of corrosion of the WZ31 alloy changes with the decrease in the grain size from a relatively uniform to a highly localized corrosion. In contrast, the ZX10 alloy showed a decrease in the corrosion rate with the decreasing grain size, but the corrosion type did not change.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"18 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":"132226258","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: 10.18323/2782-4039-2023-1-23-32
I. Zybin, M. S. Antokhin
One of the important parameters ensuring the production of a welded joint without continuity defects during friction stir welding is the provision of the required temperature in the metal bonding zone. Significant difficulties arise when determining experimentally the temperature directly in the stir zone of metals using thermocouples. In this regard, the application of numerical methods describing the distribution of temperature fields during friction stir welding is relevant. In the work, numerical modeling of temperature fields during friction stir welding was used, which was based on the finite element method using Abaqus/Explicit software. Modeling was carried out taking into account the coupled Euler – Lagrange approach, the Johnson – Cook plasticity model, and the Coulomb friction law. Using the finite element method, the models of a part, substrate, and tool were constructed taking into account their thermophysical properties. To reduce the computation time, an approach based on the metal mass scaling by recalculating the density of the metal and its thermal properties was used. The authors matched coefficients of scaling of the material mass and heat capacity for the selected welding mode parameters. To evaluate the validity of the results of numerical modeling of temperature fields during friction stir welding, the experimental research of the temperature fields using thermocouples was carried out. The paper shows the possibility of numerical modeling of temperature fields during friction stir welding with the help of the coupled Euler – Lagrange approach and Abaqus/Explicit software. Due to the application of the approach associated with material mass scaling, the calculation time is reduced by more than 10 times.
{"title":"Numerical modeling of temperature fields during friction stir welding of the AA5083 aluminum alloy","authors":"I. Zybin, M. S. Antokhin","doi":"10.18323/2782-4039-2023-1-23-32","DOIUrl":"https://doi.org/10.18323/2782-4039-2023-1-23-32","url":null,"abstract":"One of the important parameters ensuring the production of a welded joint without continuity defects during friction stir welding is the provision of the required temperature in the metal bonding zone. Significant difficulties arise when determining experimentally the temperature directly in the stir zone of metals using thermocouples. In this regard, the application of numerical methods describing the distribution of temperature fields during friction stir welding is relevant. In the work, numerical modeling of temperature fields during friction stir welding was used, which was based on the finite element method using Abaqus/Explicit software. Modeling was carried out taking into account the coupled Euler – Lagrange approach, the Johnson – Cook plasticity model, and the Coulomb friction law. Using the finite element method, the models of a part, substrate, and tool were constructed taking into account their thermophysical properties. To reduce the computation time, an approach based on the metal mass scaling by recalculating the density of the metal and its thermal properties was used. The authors matched coefficients of scaling of the material mass and heat capacity for the selected welding mode parameters. To evaluate the validity of the results of numerical modeling of temperature fields during friction stir welding, the experimental research of the temperature fields using thermocouples was carried out. The paper shows the possibility of numerical modeling of temperature fields during friction stir welding with the help of the coupled Euler – Lagrange approach and Abaqus/Explicit software. Due to the application of the approach associated with material mass scaling, the calculation time is reduced by more than 10 times.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"54 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":"127798500","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: 10.18323/2782-4039-2022-3-2-7-15
I. M. Modina, G. Dyakonov, A. Stotskiy, D. T. Miftakhov, I. Semenova
The wide use of two-phase titanium alloys in aircraft engine building, as well as the intense development of this industry, stipulate more and more stringent requirements to structural materials and the enhancement of their reliability, strength and performance characteristics. The formation of an ultrafine-grained (UFG) state in metals and alloys using severe plastic deformation (SPD) processing enables achieving high strength properties. However, an important aspect of UFG materials is their structural and textural effects which may lead to a strong anisotropy of their properties. In this respect, the authors studied the effect of microstructural features on the mechanical properties and impact toughness of the VT6 alloy after equal-channel angular pressing (ECAP) and subsequent deformation by upsetting, imitating die forging. The study showed that the formation of a UFG structure in the VT6 titanium alloy with a grain size of about 0.4 µm allows increasing the ultimate tensile strength up to 1250 MPa. The additional upsetting of the UFG alloy at T=750 °C leads to grain growth up to 0.5–1 µm and a decline in strength to 1090 MPa as a result of the recovery and recrystallization processes. Impact toughness tests were conducted on specimens with a V-shaped stress raiser at room temperature, showing that the impact toughness of the UFG VT6 alloy was 0.41 MJ/m2. The tests revealed the anisotropy of impact toughness in the UFG VT6 alloy after equal-channel angular pressing and additional upsetting due to the metallographic and crystallographic texture formed as the result of deformation treatment. In test direction No. 1, the impact toughness value is the lowest and equals 0.31 MJ/m2.
{"title":"Impact strength of VT6 titanium alloy with the ultra-fine grain structure produced by the equal-channel angular pressing method","authors":"I. M. Modina, G. Dyakonov, A. Stotskiy, D. T. Miftakhov, I. Semenova","doi":"10.18323/2782-4039-2022-3-2-7-15","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-3-2-7-15","url":null,"abstract":"The wide use of two-phase titanium alloys in aircraft engine building, as well as the intense development of this industry, stipulate more and more stringent requirements to structural materials and the enhancement of their reliability, strength and performance characteristics. The formation of an ultrafine-grained (UFG) state in metals and alloys using severe plastic deformation (SPD) processing enables achieving high strength properties. However, an important aspect of UFG materials is their structural and textural effects which may lead to a strong anisotropy of their properties. In this respect, the authors studied the effect of microstructural features on the mechanical properties and impact toughness of the VT6 alloy after equal-channel angular pressing (ECAP) and subsequent deformation by upsetting, imitating die forging. The study showed that the formation of a UFG structure in the VT6 titanium alloy with a grain size of about 0.4 µm allows increasing the ultimate tensile strength up to 1250 MPa. The additional upsetting of the UFG alloy at T=750 °C leads to grain growth up to 0.5–1 µm and a decline in strength to 1090 MPa as a result of the recovery and recrystallization processes. Impact toughness tests were conducted on specimens with a V-shaped stress raiser at room temperature, showing that the impact toughness of the UFG VT6 alloy was 0.41 MJ/m2. The tests revealed the anisotropy of impact toughness in the UFG VT6 alloy after equal-channel angular pressing and additional upsetting due to the metallographic and crystallographic texture formed as the result of deformation treatment. In test direction No. 1, the impact toughness value is the lowest and equals 0.31 MJ/m2.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"366 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":"133848046","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: 10.18323/2782-4039-2023-2-64-8
I. Rastegaev, M. R. Shafeev, I. Rastegaeva, A. Polunin, M. M. Krishtal
The paper analyzes the features of the acoustic emission (AE) signal generation during plasma-electrolytic oxidation (PEO) of the AMg6 aluminum alloy in a bipolar (anode-cathode) pulsed mode within each cycle of voltage application. The authors studied the range of PEO modes that almost completely covers all standard technological modes for processing aluminum alloys by the current densities (6–18 A/dm2) and current ratio in half-cycles (0.7–1.3), which allowed fixing and studying the AE accompanying the formation of oxide layers for various purposes. For the first time, due to AE registration, a new PEO stage was identified, in which there was no microarc breakdown to the substrate, but which was accompanied by an increase in the layer thickness, and the nature of which has not yet been determined. According to the known features of the oxidation stages, the authors systematized the repetitive forms of AE manifestation in the cycles of exposure and identified their five types and three subtypes. The study shows that the approach used to establish the PEO stages by the “acoustic emission amplitude” parameter has poor accuracy, since it does not take into account the form of signals and the half-period of their registration. Therefore, the authors developed and tested a new approach for analyzing AE frames synchronously with the cycles of change in the forming voltage during PEO, and proposed a new “acoustic-emission median” parameter, which allows identifying the main types and subtypes of signals accompanying the oxidation stages. An experimental study of the proposed AE parameter was carried out to identify these PEO stages, which confirmed the operability, high accuracy and sensitivity of the proposed parameter to the subtypes of AE signals recorded at the cathode stage of “soft sparking”. The latter is of particular interest, since it is a means of studying a given oxidation stage with a resolution equal to the exposure cycle.
{"title":"Cyclic regularities of the acoustic emission generation during plasma-electrolytic oxidation of an Al–Mg alloy in the bipolar mode","authors":"I. Rastegaev, M. R. Shafeev, I. Rastegaeva, A. Polunin, M. M. Krishtal","doi":"10.18323/2782-4039-2023-2-64-8","DOIUrl":"https://doi.org/10.18323/2782-4039-2023-2-64-8","url":null,"abstract":"The paper analyzes the features of the acoustic emission (AE) signal generation during plasma-electrolytic oxidation (PEO) of the AMg6 aluminum alloy in a bipolar (anode-cathode) pulsed mode within each cycle of voltage application. The authors studied the range of PEO modes that almost completely covers all standard technological modes for processing aluminum alloys by the current densities (6–18 A/dm2) and current ratio in half-cycles (0.7–1.3), which allowed fixing and studying the AE accompanying the formation of oxide layers for various purposes. For the first time, due to AE registration, a new PEO stage was identified, in which there was no microarc breakdown to the substrate, but which was accompanied by an increase in the layer thickness, and the nature of which has not yet been determined. According to the known features of the oxidation stages, the authors systematized the repetitive forms of AE manifestation in the cycles of exposure and identified their five types and three subtypes. The study shows that the approach used to establish the PEO stages by the “acoustic emission amplitude” parameter has poor accuracy, since it does not take into account the form of signals and the half-period of their registration. Therefore, the authors developed and tested a new approach for analyzing AE frames synchronously with the cycles of change in the forming voltage during PEO, and proposed a new “acoustic-emission median” parameter, which allows identifying the main types and subtypes of signals accompanying the oxidation stages. An experimental study of the proposed AE parameter was carried out to identify these PEO stages, which confirmed the operability, high accuracy and sensitivity of the proposed parameter to the subtypes of AE signals recorded at the cathode stage of “soft sparking”. The latter is of particular interest, since it is a means of studying a given oxidation stage with a resolution equal to the exposure cycle.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"10 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":"115325428","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: 10.18323/2782-4039-2022-1-24-30
A. M. Gnusina, N. Gryzunova
Magnesium, its compounds, and alloys arise recently the heightened interest among scientists all over the world. The interest in magnesium research is caused by its combination of many promising properties that find practical application in various sectors of the national economy. On an industrial scale, the bulk of magnesium is produced by the electrolysis from the melt. However, there is a problem with the environmental security of this process. This method is environmentally unfriendly since it is accompanied by the release of hazardous chlorine and organochlorine compounds into the environment. In some cases, the electrodeposition from solutions may serve as an alternative. The task to produce magnesium and magnesium-containing coatings using electrodeposition from solutions was already raised, but it is not yet possible to obtain a stable electrolyte that allows obtaining high-quality coatings. The authors propose an electrolyte in which isopropyl alcohol is used as a solvent. Magnesium-containing coatings were produced by electrodeposition on a conductive base. The authors prepared an electrolyte based on anhydrous magnesium sulfate. To increase the conductivity of the electrolyte, sodium, potassium, and calcium chlorides in different concentrations were added to the solution. The authors carried out the experimental studies of the effect of the electrolyte composition and electrodeposition modes on the morphology and elemental composition of magnesium-containing coatings. Electron microscopic studies and the studies of the elemental composition of samples by the energy-dispersive X-ray fluorescence spectrometer show that the non-stationary (two-step) electrodeposition mode is the optimal one for producing magnesium coatings with a fine crystalline structure, low porosity, and high magnesium content.
{"title":"ELECTROLYTIC PRODUCTION OF MAGNESIUM COATINGS","authors":"A. M. Gnusina, N. Gryzunova","doi":"10.18323/2782-4039-2022-1-24-30","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-1-24-30","url":null,"abstract":"Magnesium, its compounds, and alloys arise recently the heightened interest among scientists all over the world. The interest in magnesium research is caused by its combination of many promising properties that find practical application in various sectors of the national economy. On an industrial scale, the bulk of magnesium is produced by the electrolysis from the melt. However, there is a problem with the environmental security of this process. This method is environmentally unfriendly since it is accompanied by the release of hazardous chlorine and organochlorine compounds into the environment. In some cases, the electrodeposition from solutions may serve as an alternative. The task to produce magnesium and magnesium-containing coatings using electrodeposition from solutions was already raised, but it is not yet possible to obtain a stable electrolyte that allows obtaining high-quality coatings. The authors propose an electrolyte in which isopropyl alcohol is used as a solvent. Magnesium-containing coatings were produced by electrodeposition on a conductive base. The authors prepared an electrolyte based on anhydrous magnesium sulfate. To increase the conductivity of the electrolyte, sodium, potassium, and calcium chlorides in different concentrations were added to the solution. The authors carried out the experimental studies of the effect of the electrolyte composition and electrodeposition modes on the morphology and elemental composition of magnesium-containing coatings. Electron microscopic studies and the studies of the elemental composition of samples by the energy-dispersive X-ray fluorescence spectrometer show that the non-stationary (two-step) electrodeposition mode is the optimal one for producing magnesium coatings with a fine crystalline structure, low porosity, and high magnesium content.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"473 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":"116188011","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: 10.18323/2782-4039-2022-2-92-104
I. Torubarov, A. Drobotov, I. Gushchin, D. Vdovin, A. Plotnikov, A. Yakovlev
One of the key challenges in additive manufacturing of plastic goods using the Fused Filament Fabrication (FFF) technology is to ensure their strength. The low strength of polymer materials and the distinct anisotropy of their mechanical properties limit the use of 3D printing as an alternative to the traditional small-scale production technologies. The most promising solution to the goal of increasing the strength of printed goods is the application of continuous fiber reinforcement. Several additive manufacturing devices and software products that allow preparing a control program for 3D printing with reinforcement are known, however, having all their advantages, they, like conventional printed products, have a wide spread in strength in various directions (in the plane of a layer and perpendicularly to it, in the direction of growing). In this paper, the authors propose using the continuous fiber reinforcement along the three-dimensional trajectories to smooth out the anisotropy of the products’ properties in the FFF technology and ensure wider possibilities for using them in the production of final goods. In the course of work, a 3D printer with the ability to print using five degrees of freedom and software for preparation of control programs were upgraded for the printing process with laying continuous fiber; printing modes with reinforcement were developed; samples were produced for standard static bending tests. The experiments show that reinforcement improves the printed specimen’s strength, and the proposed three-dimensional reinforcement technique ensures the lower flexing strength compared to standard flat reinforcement with uniaxial laying of fibers, though, the destruction of 3D reinforced specimens occurred without evident delamination.
{"title":"Additive manufacturing of parts with three-dimensional continuous fiber reinforcement","authors":"I. Torubarov, A. Drobotov, I. Gushchin, D. Vdovin, A. Plotnikov, A. Yakovlev","doi":"10.18323/2782-4039-2022-2-92-104","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-2-92-104","url":null,"abstract":"One of the key challenges in additive manufacturing of plastic goods using the Fused Filament Fabrication (FFF) technology is to ensure their strength. The low strength of polymer materials and the distinct anisotropy of their mechanical properties limit the use of 3D printing as an alternative to the traditional small-scale production technologies. The most promising solution to the goal of increasing the strength of printed goods is the application of continuous fiber reinforcement. Several additive manufacturing devices and software products that allow preparing a control program for 3D printing with reinforcement are known, however, having all their advantages, they, like conventional printed products, have a wide spread in strength in various directions (in the plane of a layer and perpendicularly to it, in the direction of growing). In this paper, the authors propose using the continuous fiber reinforcement along the three-dimensional trajectories to smooth out the anisotropy of the products’ properties in the FFF technology and ensure wider possibilities for using them in the production of final goods. In the course of work, a 3D printer with the ability to print using five degrees of freedom and software for preparation of control programs were upgraded for the printing process with laying continuous fiber; printing modes with reinforcement were developed; samples were produced for standard static bending tests. The experiments show that reinforcement improves the printed specimen’s strength, and the proposed three-dimensional reinforcement technique ensures the lower flexing strength compared to standard flat reinforcement with uniaxial laying of fibers, though, the destruction of 3D reinforced specimens occurred without evident delamination.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"674 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":"123221391","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: 10.18323/2782-4039-2022-2-105-112
G. D. Khudododova, O. Kulyasova, R. Nafikov, R. Islamgaliev
It is known, that magnesium-based alloys are the appropriate materials to be used as biodegradable metals to produce new-generation medical implants. Magnesium can decompose in the human body during the healing process. If dissolution is controlled, there is no need in additional operation for implant removal after healing completion. Particularly, Mg-Zn-Ca alloys are considered the most appropriate biodegradable metal implants due to their biocompatibility. In the Mg-Zn-Ca alloys, the addition of Zn and Ca as alloying elements can improve the mechanical properties and increase the corrosion resistance compared to pure Mg without affecting biocompatibility. The work covers the study of the structure and mechanical properties of the magnesium Mg-1%Zn-0.2%Ca alloy after severe plastic deformation (SPD). The research of the structure was carried out using scanning and transmission electron microscopy. The study of mechanical properties was carried out by measuring microhardness and tension tests. The study shows that applying the equal channel angular pressing (ECAP) method and additional treatment with the severe plastic deformation (SPD) method to the Mg–1%Zn–0.2%Ca alloy leads to the formation of the ultra-fine grain (UFG) structure with the average grain size of less than 1 micron. The authors identified that, as a result of strong refinement of the magnesium alloy grain structure, the ultimate strength increases twice up to 283 MPa compared to the homogenized state, when the ultimate strength is 125 MPa. At the same time, in the UFG state, the plasticity significantly decreases up to 3 %.
{"title":"The structure and mechanical properties of biomedical magnesium alloy Mg–1%Zn–0.2%Ca","authors":"G. D. Khudododova, O. Kulyasova, R. Nafikov, R. Islamgaliev","doi":"10.18323/2782-4039-2022-2-105-112","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-2-105-112","url":null,"abstract":"It is known, that magnesium-based alloys are the appropriate materials to be used as biodegradable metals to produce new-generation medical implants. Magnesium can decompose in the human body during the healing process. If dissolution is controlled, there is no need in additional operation for implant removal after healing completion. Particularly, Mg-Zn-Ca alloys are considered the most appropriate biodegradable metal implants due to their biocompatibility. In the Mg-Zn-Ca alloys, the addition of Zn and Ca as alloying elements can improve the mechanical properties and increase the corrosion resistance compared to pure Mg without affecting biocompatibility. The work covers the study of the structure and mechanical properties of the magnesium Mg-1%Zn-0.2%Ca alloy after severe plastic deformation (SPD). The research of the structure was carried out using scanning and transmission electron microscopy. The study of mechanical properties was carried out by measuring microhardness and tension tests. The study shows that applying the equal channel angular pressing (ECAP) method and additional treatment with the severe plastic deformation (SPD) method to the Mg–1%Zn–0.2%Ca alloy leads to the formation of the ultra-fine grain (UFG) structure with the average grain size of less than 1 micron. The authors identified that, as a result of strong refinement of the magnesium alloy grain structure, the ultimate strength increases twice up to 283 MPa compared to the homogenized state, when the ultimate strength is 125 MPa. At the same time, in the UFG state, the plasticity significantly decreases up to 3 %.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"4 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":"130174609","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: 10.18323/2782-4039-2022-4-70-80
A. Nazaryev, P. Bochkarev
The problem of improving the production of highly-precise devices and machines has primary importance. It is caused by the fact that the quality and accuracy of production of such devices impose increasingly stringent requirements, while standard approaches intended to ensure these criteria are insufficiently multipurpose. The developed approach – a complex of formalized design procedures for systems for accounting the requirements for the assembly of highly-precise goods when designing technological processes of mechanical treatment – allows solving these problems. However, it is necessary to develop additional solutions to ensure the relationship between the design and technological preproduction. The relevance of the study is in the solution of an important problem – the improvement of the procedure for carrying out the design-dimensional analysis within the system for accounting the requirements for the assembly of highly-precise products when designing technological processes of mechanical treatment. To solve this issue, the authors proposed the technique of component separation of a highly-precise good based on the identification of a base component / assembly unit and specified a mathematical model for the formation of a conjugation graph and a dimension graph, which is necessary to identify critical (vital) requirements to assembly and carrying out the design-dimensional analysis. Introducing the proposed techniques will allow choosing rational technologies for producing parts at further stages of implementation of design procedures of the system for accounting the requirements for the assembly of highly-precise goods when designing technological processes of mechanical treatment. In turn, it will cause labor intensity reduction and cutting the time of production of highly-precise goods and will allow decreasing costs during design-technological preparation within the conditions of multiproduct manufacture.
{"title":"The development of methodological and mathematical tools for implementing the strategy of identifying critical requirements for assembling highly-precise goods","authors":"A. Nazaryev, P. Bochkarev","doi":"10.18323/2782-4039-2022-4-70-80","DOIUrl":"https://doi.org/10.18323/2782-4039-2022-4-70-80","url":null,"abstract":"The problem of improving the production of highly-precise devices and machines has primary importance. It is caused by the fact that the quality and accuracy of production of such devices impose increasingly stringent requirements, while standard approaches intended to ensure these criteria are insufficiently multipurpose. The developed approach – a complex of formalized design procedures for systems for accounting the requirements for the assembly of highly-precise goods when designing technological processes of mechanical treatment – allows solving these problems. However, it is necessary to develop additional solutions to ensure the relationship between the design and technological preproduction. The relevance of the study is in the solution of an important problem – the improvement of the procedure for carrying out the design-dimensional analysis within the system for accounting the requirements for the assembly of highly-precise products when designing technological processes of mechanical treatment. To solve this issue, the authors proposed the technique of component separation of a highly-precise good based on the identification of a base component / assembly unit and specified a mathematical model for the formation of a conjugation graph and a dimension graph, which is necessary to identify critical (vital) requirements to assembly and carrying out the design-dimensional analysis. Introducing the proposed techniques will allow choosing rational technologies for producing parts at further stages of implementation of design procedures of the system for accounting the requirements for the assembly of highly-precise goods when designing technological processes of mechanical treatment. In turn, it will cause labor intensity reduction and cutting the time of production of highly-precise goods and will allow decreasing costs during design-technological preparation within the conditions of multiproduct manufacture.","PeriodicalId":251458,"journal":{"name":"Frontier materials & technologies","volume":"30 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":"125151899","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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