Pub Date : 2023-01-01DOI: 10.30791/1028-978x-2023-2-32-43
N. V. Sidorov, A. Kadetova, M. Smirnov, R. Titov, N. Teplyakova, M. Palatnikov
Features of the defect structure of nominally pure LiNbO3:В crystals were investigated by X-ray diffraction analysis and photoluminescence. Crystals were grown by the Czochralski from a mixture of congruent composition charge containing 0.08 and 0.12 wt. % boron. At this, the concentration of boron in crystals is at the level of trace amounts of metallic impurities and is ~ 10–4 wt%. MeO6 oxygen-octahedral clusters are responsible for the ferroelectric and nonlinear optical properties of the crystal. It has been found that in LiNbO3:B crystals, the lengths of O–O, Me–O, and Me–Me (Me–Li, Nb) bonds in clusters, the arrangement of Me cations, vacancies, and NbLi point defects along the polar axis differ significantly from those for nominally pure congruent crystal. NbLi defects and transition metals are deep electron traps responsible for the photorefraction effect. The photoluminescence spectra showed that the concentration of defects and metals in the investigated LiNbO3:B crystals is lower than in the congruent crystal. these differences can be due to both a change in the properties of the boron-containing melt and the localization of trace amounts of boron in the O4 tetrahedral gaps of the LiNbO3 crystal structure. In the first case, reactive boron binds cations of niobium and transition metals in the melt into stable complexes.
{"title":"Features of the defect structure and photoluminescence of nominally pure LiNbO3 crystals grown from boron doped charge","authors":"N. V. Sidorov, A. Kadetova, M. Smirnov, R. Titov, N. Teplyakova, M. Palatnikov","doi":"10.30791/1028-978x-2023-2-32-43","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-2-32-43","url":null,"abstract":"Features of the defect structure of nominally pure LiNbO3:В crystals were investigated by X-ray diffraction analysis and photoluminescence. Crystals were grown by the Czochralski from a mixture of congruent composition charge containing 0.08 and 0.12 wt. % boron. At this, the concentration of boron in crystals is at the level of trace amounts of metallic impurities and is ~ 10–4 wt%. MeO6 oxygen-octahedral clusters are responsible for the ferroelectric and nonlinear optical properties of the crystal. It has been found that in LiNbO3:B crystals, the lengths of O–O, Me–O, and Me–Me (Me–Li, Nb) bonds in clusters, the arrangement of Me cations, vacancies, and NbLi point defects along the polar axis differ significantly from those for nominally pure congruent crystal. NbLi defects and transition metals are deep electron traps responsible for the photorefraction effect. The photoluminescence spectra showed that the concentration of defects and metals in the investigated LiNbO3:B crystals is lower than in the congruent crystal. these differences can be due to both a change in the properties of the boron-containing melt and the localization of trace amounts of boron in the O4 tetrahedral gaps of the LiNbO3 crystal structure. In the first case, reactive boron binds cations of niobium and transition metals in the melt into stable complexes.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74600246","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-7-23-33
M. Kalinina, D. A. Dyuskina, T. V. Khamova, L. N. Yefimova, I. Kruchinina, O. Shilova
By liquid-phase methods of synthesis: by the method of co-precipitation of hydroxides and co-crystallization of nitrate salts, highly dispersed mesoporous powders of the composition are synthesized: (SeO2)1 – x(Nd2O3)x (х = 0,05; 0,10; 0,15; 0,20, 0,25), having a specific pore volume of 0.030 – 0.111 cm3/g and a specific surface area of 7.40 – 119.26 m2/g. Based on them, ceramic nanomaterials of a given composition with CSR ~ 69 – 88 nm (1300 °С) were obtained. The physicochemical properties of the resulting ceramics have been studied; it was revealed that it is a solid solution with open porosity in the range of 17 – 30 %, high values of relative density of 89 – 96 %. In terms of their physicochemical properties (density, thermal expansion coefficient), the resulting ceramic materials are promising as solid oxide electrolytes for medium-temperature fuel cells.
{"title":"Effect of synthesis conditions on the physicochemical properties of хerogels, nanopowders and ceramic materials in the CeO2 – Nd2O3 system","authors":"M. Kalinina, D. A. Dyuskina, T. V. Khamova, L. N. Yefimova, I. Kruchinina, O. Shilova","doi":"10.30791/1028-978x-2023-7-23-33","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-7-23-33","url":null,"abstract":"By liquid-phase methods of synthesis: by the method of co-precipitation of hydroxides and co-crystallization of nitrate salts, highly dispersed mesoporous powders of the composition are synthesized: (SeO2)1 – x(Nd2O3)x (х = 0,05; 0,10; 0,15; 0,20, 0,25), having a specific pore volume of 0.030 – 0.111 cm3/g and a specific surface area of 7.40 – 119.26 m2/g. Based on them, ceramic nanomaterials of a given composition with CSR ~ 69 – 88 nm (1300 °С) were obtained. The physicochemical properties of the resulting ceramics have been studied; it was revealed that it is a solid solution with open porosity in the range of 17 – 30 %, high values of relative density of 89 – 96 %. In terms of their physicochemical properties (density, thermal expansion coefficient), the resulting ceramic materials are promising as solid oxide electrolytes for medium-temperature fuel cells.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73066337","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-7-73-83
Yu. G. Sokolovskaya, N. Podymova, A. Karabutov
The paper presents a method for quantifying the porosity of carbon fiber structures based on laser excitation of probing ultrasonic pulses. A method for estimating the porosity of a material from the experimentally measured phase velocity of longitudinal acoustic waves propagating in it is proposed. Using the example of control samples and real structures made of carbon fiber, the possibility of obtaining distributions of local porosity values in the studied section of the structure is demonstrated. It is shown that in the studied structures there are regions with a significant variation in the value of local porosity. The proposed method can be used to control the quality of manufactured composite structures, as well as to study the internal changes in structure during operation.
{"title":"Laser-ultrasonic study of local porosity distribution in CFRP stringer panels","authors":"Yu. G. Sokolovskaya, N. Podymova, A. Karabutov","doi":"10.30791/1028-978x-2023-7-73-83","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-7-73-83","url":null,"abstract":"The paper presents a method for quantifying the porosity of carbon fiber structures based on laser excitation of probing ultrasonic pulses. A method for estimating the porosity of a material from the experimentally measured phase velocity of longitudinal acoustic waves propagating in it is proposed. Using the example of control samples and real structures made of carbon fiber, the possibility of obtaining distributions of local porosity values in the studied section of the structure is demonstrated. It is shown that in the studied structures there are regions with a significant variation in the value of local porosity. The proposed method can be used to control the quality of manufactured composite structures, as well as to study the internal changes in structure during operation.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73602902","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-1-66-79
M. Boldin, A. Popov, G. Shcherbak, K. Smetanina, D. Permin, V. A. Koshkin, A. Nokhrin, V. Chuvil’deev, А. А. Moskvichev, A. Murashov
The effect of the lithium chloride and lithium fluoride additives (2 wt. %) on the kinetics of Spark Plasma Sintering of industrial fine alumina powder was investigated. The Al2O3 + 2 % LiF powder was obtained by mixing the α-Al2O3 fine powders with the aqueous solution of LiF. The Al2O3 + 2 % LiCl fine powder was obtained by joint grinding of the components in a planetary mill. The sintering of the powders was performed with the heating rates of 10 and 50 °C/min up to the temperature corresponding to the end of the shrinkage. The ceramics sintered with the heating rate of 10 °C/min had the relative density of 97.4 – 98.7 %. The addition of lithium fluoride into the alumina powder was found to allow reducing the temperature of the beginning of the intensive powder shrinkage from 1400 – 1500 °C down to 1255 – 1335 °C. LiCl was shown to evaporate at low heating temperatures and not to affect the compaction intensity of the Al2O3 powder. The presence of the overheated LiF melt (not having enough time to evaporate from the specimen volume completely) in the ceramics leads to the appearance of the residual porosity and to the reduction of the hardness of the ceramics. Using the Young – Cutler equation, the powder compaction mechanisms were determined for pure alumina α-Al2O3 and for the powder compositions with the LiCl and LiF additives in the rapid heating conditions. The sintering activation energy was shown to be close to the one of the grain boundary diffusion. The LiF melt was found to promote the sliding of the Al2O3 fine particles during the low-temperature compaction stage.
{"title":"Investigation of the effect of LiCl and LiF additives on the kinetics of Spark Plasma Sintering of fine-grained alumina","authors":"M. Boldin, A. Popov, G. Shcherbak, K. Smetanina, D. Permin, V. A. Koshkin, A. Nokhrin, V. Chuvil’deev, А. А. Moskvichev, A. Murashov","doi":"10.30791/1028-978x-2023-1-66-79","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-1-66-79","url":null,"abstract":"The effect of the lithium chloride and lithium fluoride additives (2 wt. %) on the kinetics of Spark Plasma Sintering of industrial fine alumina powder was investigated. The Al2O3 + 2 % LiF powder was obtained by mixing the α-Al2O3 fine powders with the aqueous solution of LiF. The Al2O3 + 2 % LiCl fine powder was obtained by joint grinding of the components in a planetary mill. The sintering of the powders was performed with the heating rates of 10 and 50 °C/min up to the temperature corresponding to the end of the shrinkage. The ceramics sintered with the heating rate of 10 °C/min had the relative density of 97.4 – 98.7 %. The addition of lithium fluoride into the alumina powder was found to allow reducing the temperature of the beginning of the intensive powder shrinkage from 1400 – 1500 °C down to 1255 – 1335 °C. LiCl was shown to evaporate at low heating temperatures and not to affect the compaction intensity of the Al2O3 powder. The presence of the overheated LiF melt (not having enough time to evaporate from the specimen volume completely) in the ceramics leads to the appearance of the residual porosity and to the reduction of the hardness of the ceramics. Using the Young – Cutler equation, the powder compaction mechanisms were determined for pure alumina α-Al2O3 and for the powder compositions with the LiCl and LiF additives in the rapid heating conditions. The sintering activation energy was shown to be close to the one of the grain boundary diffusion. The LiF melt was found to promote the sliding of the Al2O3 fine particles during the low-temperature compaction stage.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87831234","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-7-46-56
E. G. Kuznetsova, V. A. Ryzhikova, L. A. Salomatina, O. M. Kuryleva, V. Sevastianov
Recently, antioxidants, one of which is nicotinamide, have often been used in the treatment of a number of chronic cardiovascular, autoimmune, skin diseases, and diabetes mellitus. Taking into account the frequent and long-term use of nicotinamide, it seems appropriate to the authors to create a new dosage form of a transdermal therapeutic system (TTS) capable of maintaining the required level of the drug concentration in the blood for a long time. The aim of the work was to develop and to study the functional properties of a system for percutaneous delivery of nicotinamide in vitro. Four compositions of the percutaneous delivery emulsion system for the nicotinamide TTS were suggested, in which the amount of the percutaneous carrier of sodium docusate was varied. Studies of the diffusion of nicotinamide in vitro through unconserved rabbit skin have shown that an increase in the concentration of sodium docusate by three times (from 3.3 % to 9.8 %) significantly increases the amount of the diffused drug substance by 15% and decreases the amount of nicotinamide remaining in the TTS. The amount of the antioxidant founded in the skin flap was lower than the therapeutic dose (~ 1.46 % of its initial amount in TTS) 24 hours after the start of the in vitro experiment. It indicates the absence of a possible aftereffect of nicotinamide TTS in its clinical use after detaching from the patient’s skin.
{"title":"Percutaneous delivery system for nicotinamide transdermal therapeutic system","authors":"E. G. Kuznetsova, V. A. Ryzhikova, L. A. Salomatina, O. M. Kuryleva, V. Sevastianov","doi":"10.30791/1028-978x-2023-7-46-56","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-7-46-56","url":null,"abstract":"Recently, antioxidants, one of which is nicotinamide, have often been used in the treatment of a number of chronic cardiovascular, autoimmune, skin diseases, and diabetes mellitus. Taking into account the frequent and long-term use of nicotinamide, it seems appropriate to the authors to create a new dosage form of a transdermal therapeutic system (TTS) capable of maintaining the required level of the drug concentration in the blood for a long time. The aim of the work was to develop and to study the functional properties of a system for percutaneous delivery of nicotinamide in vitro. Four compositions of the percutaneous delivery emulsion system for the nicotinamide TTS were suggested, in which the amount of the percutaneous carrier of sodium docusate was varied. Studies of the diffusion of nicotinamide in vitro through unconserved rabbit skin have shown that an increase in the concentration of sodium docusate by three times (from 3.3 % to 9.8 %) significantly increases the amount of the diffused drug substance by 15% and decreases the amount of nicotinamide remaining in the TTS. The amount of the antioxidant founded in the skin flap was lower than the therapeutic dose (~ 1.46 % of its initial amount in TTS) 24 hours after the start of the in vitro experiment. It indicates the absence of a possible aftereffect of nicotinamide TTS in its clinical use after detaching from the patient’s skin.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86394165","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-4-42-49
V. Kataev, M. A. Fedotov, N. A. Andreeva, A. Fomina, V. A. Volchenkova, A. A. Alpatov
A polydisperse nanopowder of iron oxide, consisting of hematite α-Fe2O3 and magnetite Fe3O4, was obtained by the method of solid-phase reduction of iron hydroxide Fe(OH)3. On the basis of the obtained iron oxide nanopowder, aqueous suspensions were prepared in the concentration range of 0.25 – 1.25 mg/l with a particle dispersion of 100 – 400 nm. To assess the biological activity of iron oxide nanopowder, pre-sowing treatment of corn seeds Zéa máys was carried out. It has been established that the treatment with nanoparticles has a stimulating effect on the development of the plant organism, making it possible to achieve an increase in germination by 15% and root mass by 23%. Determination of the quantitative content of iron in different parts of the plant was carried out using atomic emission and atomic absorption spectroscopy. It was shown that as a result of treatment of plants with iron nanoparticles, its accumulation in the root mass with subsequent redistribution to the leaves to stimulate the process of photosynthesis is observed.
{"title":"Research of nanosized iron oxide powder as a biologically active material","authors":"V. Kataev, M. A. Fedotov, N. A. Andreeva, A. Fomina, V. A. Volchenkova, A. A. Alpatov","doi":"10.30791/1028-978x-2023-4-42-49","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-4-42-49","url":null,"abstract":"A polydisperse nanopowder of iron oxide, consisting of hematite α-Fe2O3 and magnetite Fe3O4, was obtained by the method of solid-phase reduction of iron hydroxide Fe(OH)3. On the basis of the obtained iron oxide nanopowder, aqueous suspensions were prepared in the concentration range of 0.25 – 1.25 mg/l with a particle dispersion of 100 – 400 nm. To assess the biological activity of iron oxide nanopowder, pre-sowing treatment of corn seeds Zéa máys was carried out. It has been established that the treatment with nanoparticles has a stimulating effect on the development of the plant organism, making it possible to achieve an increase in germination by 15% and root mass by 23%. Determination of the quantitative content of iron in different parts of the plant was carried out using atomic emission and atomic absorption spectroscopy. It was shown that as a result of treatment of plants with iron nanoparticles, its accumulation in the root mass with subsequent redistribution to the leaves to stimulate the process of photosynthesis is observed.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89707492","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-6-5-16
O. Rubinkovskaya, D. Fominski, V. Nevolin, R. Romanov, P. Kartsev, Hualin Jiang, V. Fominski
The possibilities of modification of the structure and type of conductivity of WSe2 films formed on p-type silicon by thermal treatment of a thin-film precursor, which was preliminarily created by pulsed laser deposition, are studied. Pulsed laser ablation of WSe2 and rhenium targets made it possible to obtain amorphous films WSex (x > 2) containing rhenium atoms and inclusions of β-W nanoparticles. Heat treatment at 450 °C caused the crystallization of the amorphous matrix and the formation of a layered 2H-WSe2 shell surrounded the metal nanoparticles. Doping with rhenium led to the production of n-type WSe2 semiconductor films, which, in terms of their properties (band gap ~ 1.2 eV, high catalytic activity, low resistance to current transport), represent a promising material for creating p-Si photocathodes for efficient light-activated hydrogen evolution in acid solution. Theoretical calculations are carried out, which make it possible to identify local areas on the surface of the formed WSe2 films with enhanced catalytic activity in hydrogen evolution reaction.
{"title":"Preparation of thin nanostructured n-WSe2 films and their application in semiconductor p-Si photocathodes for hydrogen production by water splitting","authors":"O. Rubinkovskaya, D. Fominski, V. Nevolin, R. Romanov, P. Kartsev, Hualin Jiang, V. Fominski","doi":"10.30791/1028-978x-2023-6-5-16","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-6-5-16","url":null,"abstract":"The possibilities of modification of the structure and type of conductivity of WSe2 films formed on p-type silicon by thermal treatment of a thin-film precursor, which was preliminarily created by pulsed laser deposition, are studied. Pulsed laser ablation of WSe2 and rhenium targets made it possible to obtain amorphous films WSex (x > 2) containing rhenium atoms and inclusions of β-W nanoparticles. Heat treatment at 450 °C caused the crystallization of the amorphous matrix and the formation of a layered 2H-WSe2 shell surrounded the metal nanoparticles. Doping with rhenium led to the production of n-type WSe2 semiconductor films, which, in terms of their properties (band gap ~ 1.2 eV, high catalytic activity, low resistance to current transport), represent a promising material for creating p-Si photocathodes for efficient light-activated hydrogen evolution in acid solution. Theoretical calculations are carried out, which make it possible to identify local areas on the surface of the formed WSe2 films with enhanced catalytic activity in hydrogen evolution reaction.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76084611","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-1-5-18
S. Meisner, L. Meisner
Influence of surface electron-beam processing on character of fatigue cracks propagation and crack growth rates under cyclic tension in a mode of low-cycle loading of TiNi samples before and after irradiation by low-energy high-current electron beam (LEHCEB) is studied in the work. Correlation between stages of fatigue cracks propagation and formation of plastic zones on surfaces of failure in TiNi samples before and after LEHCEB treatments is established. The LEHCEB treatment of specimen surfaces was carried out at the electron-beam installation “RITM-SP” with the electron beam parameters: energy density ES = 3.7 J/cm2, pulse duration τ = 2.5 μs, number of pulses n = 5. Differences in the stages of propagation of main fatigue cracks during cyclic stretching of TiNi samples before and after LEHCEB have been revealed. Preferential mechanisms of quasistatic and fatigue fracture at different stages of crack propagation are determined. It is shown that LEHCEB treatment leads to a shift of fatigue fracture initiation and the beginning of all stages by ∆N ≥ 3000, increasing the cyclic durability of the specimens by ~ 1.5 times. The greatest influence of surface modification is shown on Stage I of fatigue crack propagation. The lower rate of fatigue crack propagation at this stage in irradiated specimens leads to an increase in its duration as compared to unirradiated specimens. It is concluded that to effectively increase the fatigue life of TiNi specimens by means of LEHCEB treatments it is necessary to create conditions for increasing the number of cycles before the Stage I initiation and maximizing the duration of this stage.
{"title":"Effect of electron-beam treatment on the nature of fatigue crack propagation and formation of plastic zones on fracture surfaces in TiNi shape memory alloy","authors":"S. Meisner, L. Meisner","doi":"10.30791/1028-978x-2023-1-5-18","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-1-5-18","url":null,"abstract":"Influence of surface electron-beam processing on character of fatigue cracks propagation and crack growth rates under cyclic tension in a mode of low-cycle loading of TiNi samples before and after irradiation by low-energy high-current electron beam (LEHCEB) is studied in the work. Correlation between stages of fatigue cracks propagation and formation of plastic zones on surfaces of failure in TiNi samples before and after LEHCEB treatments is established. The LEHCEB treatment of specimen surfaces was carried out at the electron-beam installation “RITM-SP” with the electron beam parameters: energy density ES = 3.7 J/cm2, pulse duration τ = 2.5 μs, number of pulses n = 5. Differences in the stages of propagation of main fatigue cracks during cyclic stretching of TiNi samples before and after LEHCEB have been revealed. Preferential mechanisms of quasistatic and fatigue fracture at different stages of crack propagation are determined. It is shown that LEHCEB treatment leads to a shift of fatigue fracture initiation and the beginning of all stages by ∆N ≥ 3000, increasing the cyclic durability of the specimens by ~ 1.5 times. The greatest influence of surface modification is shown on Stage I of fatigue crack propagation. The lower rate of fatigue crack propagation at this stage in irradiated specimens leads to an increase in its duration as compared to unirradiated specimens. It is concluded that to effectively increase the fatigue life of TiNi specimens by means of LEHCEB treatments it is necessary to create conditions for increasing the number of cycles before the Stage I initiation and maximizing the duration of this stage.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76208457","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-5-66-71
G. Govor, A. Larin, O. Demidenko, A. L. Zheludkevich
Magnetic properties of composite magnetically soft (SMC) materials based on iron powder ABC100.30 depending on the thickness of the insulating coating based on phosphorus oxide are investigated. It was found that for SMC materials with a three-layer coating of particles, the magnitude of magnetic hysteresis is minimal. As a result, the remagnetization losses for a materials with three-layer insulating particles coating are reduced by an order of magnitude in comparison with composites based on powders with a single-layer coating. The developed materials with magnetic permeability µ = 100 – 150 and induction up to 1.8 T are promising for use in the frequency range up to 1 MHz in the manufacture of various types of electrical devices.
{"title":"Magnetic properties of SMC materials based on iron powder with multilayer insulating coating","authors":"G. Govor, A. Larin, O. Demidenko, A. L. Zheludkevich","doi":"10.30791/1028-978x-2023-5-66-71","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-5-66-71","url":null,"abstract":"Magnetic properties of composite magnetically soft (SMC) materials based on iron powder ABC100.30 depending on the thickness of the insulating coating based on phosphorus oxide are investigated. It was found that for SMC materials with a three-layer coating of particles, the magnitude of magnetic hysteresis is minimal. As a result, the remagnetization losses for a materials with three-layer insulating particles coating are reduced by an order of magnitude in comparison with composites based on powders with a single-layer coating. The developed materials with magnetic permeability µ = 100 – 150 and induction up to 1.8 T are promising for use in the frequency range up to 1 MHz in the manufacture of various types of electrical devices.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84907430","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 : 2023-01-01DOI: 10.30791/1028-978x-2023-6-42-51
A. Memetova, A. Zelenin, N. Memetov, V. Yagubov, N. Chapaksov, R. Stolyarov, A. Gerasimova, E. Mkrtchyan
A new microporous carbon material (MUM-51) was obtained from waste coffee grounds by carbonization and activation of KOH. MUM-51 has been characterized by various methods, including N2 adsorption-desorption at 77 K, X-ray diffraction analysis, Fourier transform IR spectroscopy, and Raman spectroscopy. Methane adsorption was studied on the resulting adsorbent at pressures up to 10 MPa and temperatures of 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15 K. The specific pore volume of the adsorbent according to DFT is VDFT = 1.604 cm3/g. The BET specific surface is SBET = 3456 m2/g. The maximum value of methane adsorption at a temperature of 298,15 K and a pressure of 10 MPa reaches ~ 19 mmol/g. Experimental data on methane adsorption on MUM-51 were analyzed using the Dubinin–Radushkevich adsorption model in the temperature range 298.15 – 323.15 K and pressures up to 10 MPa. It has been established that the average relative deviations between the experimental results and the results obtained using the Dubinin-Radushkevich model are less than 3%. The initial differential molar heat of methane adsorption on the MUM-51 adsorbent is 28.7 kJ/mol. The results of the work showed that the carbon material obtained from waste coffee grounds, which has a high specific surface area and porosity, can be effectively used as an adsorbent for greenhouse gases, in particular methane.
{"title":"Adsorption properties with respect to methane of a functional porous material based on coffee waste","authors":"A. Memetova, A. Zelenin, N. Memetov, V. Yagubov, N. Chapaksov, R. Stolyarov, A. Gerasimova, E. Mkrtchyan","doi":"10.30791/1028-978x-2023-6-42-51","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-6-42-51","url":null,"abstract":"A new microporous carbon material (MUM-51) was obtained from waste coffee grounds by carbonization and activation of KOH. MUM-51 has been characterized by various methods, including N2 adsorption-desorption at 77 K, X-ray diffraction analysis, Fourier transform IR spectroscopy, and Raman spectroscopy. Methane adsorption was studied on the resulting adsorbent at pressures up to 10 MPa and temperatures of 298.15, 303.15, 308.15, 313.15, 318.15, and 323.15 K. The specific pore volume of the adsorbent according to DFT is VDFT = 1.604 cm3/g. The BET specific surface is SBET = 3456 m2/g. The maximum value of methane adsorption at a temperature of 298,15 K and a pressure of 10 MPa reaches ~ 19 mmol/g. Experimental data on methane adsorption on MUM-51 were analyzed using the Dubinin–Radushkevich adsorption model in the temperature range 298.15 – 323.15 K and pressures up to 10 MPa. It has been established that the average relative deviations between the experimental results and the results obtained using the Dubinin-Radushkevich model are less than 3%. The initial differential molar heat of methane adsorption on the MUM-51 adsorbent is 28.7 kJ/mol. The results of the work showed that the carbon material obtained from waste coffee grounds, which has a high specific surface area and porosity, can be effectively used as an adsorbent for greenhouse gases, in particular methane.","PeriodicalId":20003,"journal":{"name":"Perspektivnye Materialy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83224092","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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