Pub Date : 2023-01-01DOI: 10.30791/1028-978x-2023-4-60-67
А. A. Nesterov, M. Tolstunov
In technology, using as precursors Fe(III) and Bi(III) nitrates, peroxo-nitrate complexes Ti(IV) and Zr(IV), as well as barium and calcium hydroxides, ultrafine powders of the (1 – у)Bi0.8Ba0.2Fe0.8Ti0.2O3 – уBa0.85Ca0.15Ti0.9Zr0.1O3 (у = 0,05 – 0,30). To reduce the electrical conductivity of ceramic samples made from these powders, the basic phases were alloyed with manganese compounds. To increase the d33 values of the piezoelectric elements, as well as to increase their operating temperature, a special sintering regime involving air hardening of the ceramic samples was used. The best samples of piezoceramics produced by the proposed technology have a Curie temperature above 550 °C and longitudinal piezoelectric modulus (standard conditions) values d33 ≥ 125 pC/N and their operating temperature reaches 340 – 350 °C.
{"title":"Technology and properties of high-temperature piezoceramic materials based on phases of the system (1 – у)(Bi0.8Ba0.2)Fe0.8Ti0.2O3 – у(Ba0.85Ca0.15)Ti0.90Zr0.10O3","authors":"А. A. Nesterov, M. Tolstunov","doi":"10.30791/1028-978x-2023-4-60-67","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-4-60-67","url":null,"abstract":"In technology, using as precursors Fe(III) and Bi(III) nitrates, peroxo-nitrate complexes Ti(IV) and Zr(IV), as well as barium and calcium hydroxides, ultrafine powders of the (1 – у)Bi0.8Ba0.2Fe0.8Ti0.2O3 – уBa0.85Ca0.15Ti0.9Zr0.1O3 (у = 0,05 – 0,30). To reduce the electrical conductivity of ceramic samples made from these powders, the basic phases were alloyed with manganese compounds. To increase the d33 values of the piezoelectric elements, as well as to increase their operating temperature, a special sintering regime involving air hardening of the ceramic samples was used. The best samples of piezoceramics produced by the proposed technology have a Curie temperature above 550 °C and longitudinal piezoelectric modulus (standard conditions) values d33 ≥ 125 pC/N and their operating temperature reaches 340 – 350 °C.","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":"83200031","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-2023-2-21-31
L. D. Ivanova, Y. Granatkina, I. Y. Nikhezina, A. G. Malchev, M. I. Zaldastanishvili, S. P. Krivoruchko, O. N. D’yakonov, R. Karima
The microstructure and thermoelectric properties of a Bi2Te3–Bi2Se3 solid solution samples containing 20 mol. % Bi2Te3 doped with Hg2Cl2 of n-type conductivity obtained by hot pressing, extrusion and spark plasma sintering of powders prepared by melt spinning and grinding the ingot in a ball mill were studied. Optical and electron scanning microscopy methods were used. The effect of the disk rotation speed on the morphology of particles obtained by melt spinning is investigated. The Seebeck coefficient, electrical conductivity and thermal conductivity were measured at room temperature and in the temperature range 100 – 700 K and the thermoelectric figure of merit was calculated. The samples had anisotropy of electrical conductivity (σ) and thermal conductivity (κ) in the direction perpendicular and parallel to the pressing, the Seebeck coefficient (α) was isotropic. At 300 K anisotropy factors σ┴/σ// ~ 2, κ┴/κ// ~ 2, α┴/α// ~ 1. The highest thermoelectric figure of merit (ZT)max = 1,0 ± 0,1 at ~ 470 K was obtained for extruded samples from powders prepared by grinding the ingot and for hot-pressed samples from powders obtained by melt spinning.
{"title":"Chalcogenides of bismuth obtained by various methods","authors":"L. D. Ivanova, Y. Granatkina, I. Y. Nikhezina, A. G. Malchev, M. I. Zaldastanishvili, S. P. Krivoruchko, O. N. D’yakonov, R. Karima","doi":"10.30791/1028-978x-2023-2-21-31","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-2-21-31","url":null,"abstract":"The microstructure and thermoelectric properties of a Bi2Te3–Bi2Se3 solid solution samples containing 20 mol. % Bi2Te3 doped with Hg2Cl2 of n-type conductivity obtained by hot pressing, extrusion and spark plasma sintering of powders prepared by melt spinning and grinding the ingot in a ball mill were studied. Optical and electron scanning microscopy methods were used. The effect of the disk rotation speed on the morphology of particles obtained by melt spinning is investigated. The Seebeck coefficient, electrical conductivity and thermal conductivity were measured at room temperature and in the temperature range 100 – 700 K and the thermoelectric figure of merit was calculated. The samples had anisotropy of electrical conductivity (σ) and thermal conductivity (κ) in the direction perpendicular and parallel to the pressing, the Seebeck coefficient (α) was isotropic. At 300 K anisotropy factors σ┴/σ// ~ 2, κ┴/κ// ~ 2, α┴/α// ~ 1. The highest thermoelectric figure of merit (ZT)max = 1,0 ± 0,1 at ~ 470 K was obtained for extruded samples from powders prepared by grinding the ingot and for hot-pressed samples from powders obtained by melt spinning.","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":"77964673","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-2023-4-76-88
E. Lantsev, A. Nokhrin, M. Boldin, K. Smetanina, A. Murashov, Yu. V. Blagoveshchenskiy, N. Isaeva, G. Shcherbak, V. Chuvil’deev, N. Tabachkova, A. Terentyev
The sintering mechanisms of WC – Al2O3 nanopowder compositions with different contents of aluminum oxide particles (1, 3, 5 wt.%) were investigated. Samples of WC – Al2O3 ceramics were produced by Spark Plasma Sintering method (SPS) in vacuum, by heating to a temperature of 1450 °C at a rate of 50 °C/min under uniaxial stress 70 MPa. Plasma-chemical nanopowders of tungsten monocarbide and submicron powders of aluminum oxide were used to make the ceramics. The density, microstructure, phase composition, microhardness (Hv) and fracture toughness (KIC) of the ceramics were investigated. It was shown that the use of the SPS method makes it possible to obtain WC-Al2O3 ceramics with good relative density (95.4-98.1%) and a homogeneous microstructure with ultrafine grain size (0.1 – 0.2 μm). By the method of the X-ray phase analysis, it was established that in the process of SPS of WC-Al2O3 ceramics the formation of an undesirable W2C phase takes place, leading to decrease in the fracture toughness KIC. To reduce the intensity of W2C particle formation, colloidal graphite (0.1, 0.2, 0.3 wt.%) was added to WC – Al2O3 ceramics. Using the Young-Cutler model and the model of diffusion resorption of pores it was shown that the main mechanism of SPS of WC – Al2O3 ceramics is grain boundary diffusion. It is shown that the introduction of graphite leads to a decrease in the activation energy of SPS of WC – Al2O3 ceramics, which is probably due to a decrease in the W2C particle content to 0.5 wt.%.
{"title":"Spark Plasma Sintering of ultrafine-grained WC – Al2O3 ceramics","authors":"E. Lantsev, A. Nokhrin, M. Boldin, K. Smetanina, A. Murashov, Yu. V. Blagoveshchenskiy, N. Isaeva, G. Shcherbak, V. Chuvil’deev, N. Tabachkova, A. Terentyev","doi":"10.30791/1028-978x-2023-4-76-88","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-4-76-88","url":null,"abstract":"The sintering mechanisms of WC – Al2O3 nanopowder compositions with different contents of aluminum oxide particles (1, 3, 5 wt.%) were investigated. Samples of WC – Al2O3 ceramics were produced by Spark Plasma Sintering method (SPS) in vacuum, by heating to a temperature of 1450 °C at a rate of 50 °C/min under uniaxial stress 70 MPa. Plasma-chemical nanopowders of tungsten monocarbide and submicron powders of aluminum oxide were used to make the ceramics. The density, microstructure, phase composition, microhardness (Hv) and fracture toughness (KIC) of the ceramics were investigated. It was shown that the use of the SPS method makes it possible to obtain WC-Al2O3 ceramics with good relative density (95.4-98.1%) and a homogeneous microstructure with ultrafine grain size (0.1 – 0.2 μm). By the method of the X-ray phase analysis, it was established that in the process of SPS of WC-Al2O3 ceramics the formation of an undesirable W2C phase takes place, leading to decrease in the fracture toughness KIC. To reduce the intensity of W2C particle formation, colloidal graphite (0.1, 0.2, 0.3 wt.%) was added to WC – Al2O3 ceramics. Using the Young-Cutler model and the model of diffusion resorption of pores it was shown that the main mechanism of SPS of WC – Al2O3 ceramics is grain boundary diffusion. It is shown that the introduction of graphite leads to a decrease in the activation energy of SPS of WC – Al2O3 ceramics, which is probably due to a decrease in the W2C particle content to 0.5 wt.%.","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":"76364710","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-2023-3-24-31
M. Davydova, A. R. Khaldeeva, A. Fedorova, M. Sokolova
The effect of vulcanization accelerators on the structure and properties of rubbers based on Hydrin T6000 epichlorohydrin rubber has been studied. Mercaptobenzthiazole (MBT) in the amount of 1.5 pts.wt., tetramethylthiuram disulfide (TMTD) — 0.5 – 1.5 pst.wt. were used as accelerators and N,N’-diphenylguanidine (DPG) — 0.5 – 1.5 pst.wt., which represent a triple system of accelerators. The choice of accelerators is based on the possibility of obtaining a vulcanization spatial structure of different sulfide content: thiuram group accelerators promote the formation of mono-, disulfide bonds; guanidine — polysulfide bonds, and thiazole groups — from carbon-carbon to polysulfide with varying degrees of sulfide. According to the results of the study of physical and mechanical properties, the determination of the parameters of the spatial grid and the study of the dynamic behavior of rubber, differences were revealed due to the formation of a spatial structure with different types of cross-links and density. It is shown that rubber containing 1.5 pst. wt. MBT, 0.5 pst. wt. DFG and 0.5 – 1.0 pst.wt. TMTD due to the manifestation of a synergistic effect on the formation of a vulcanization network of a certain density and the ratio of poly-, di- and monosulfide cross-links. Thus, the use of a group of accelerators with different functional effects makes it possible to obtain vulcanizates with an optimal set of technological and operational properties.
{"title":"Choice of accelerators of the vulcanization group for rubbers based on epichlorohydrin rubber","authors":"M. Davydova, A. R. Khaldeeva, A. Fedorova, M. Sokolova","doi":"10.30791/1028-978x-2023-3-24-31","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-3-24-31","url":null,"abstract":"The effect of vulcanization accelerators on the structure and properties of rubbers based on Hydrin T6000 epichlorohydrin rubber has been studied. Mercaptobenzthiazole (MBT) in the amount of 1.5 pts.wt., tetramethylthiuram disulfide (TMTD) — 0.5 – 1.5 pst.wt. were used as accelerators and N,N’-diphenylguanidine (DPG) — 0.5 – 1.5 pst.wt., which represent a triple system of accelerators. The choice of accelerators is based on the possibility of obtaining a vulcanization spatial structure of different sulfide content: thiuram group accelerators promote the formation of mono-, disulfide bonds; guanidine — polysulfide bonds, and thiazole groups — from carbon-carbon to polysulfide with varying degrees of sulfide. According to the results of the study of physical and mechanical properties, the determination of the parameters of the spatial grid and the study of the dynamic behavior of rubber, differences were revealed due to the formation of a spatial structure with different types of cross-links and density. It is shown that rubber containing 1.5 pst. wt. MBT, 0.5 pst. wt. DFG and 0.5 – 1.0 pst.wt. TMTD due to the manifestation of a synergistic effect on the formation of a vulcanization network of a certain density and the ratio of poly-, di- and monosulfide cross-links. Thus, the use of a group of accelerators with different functional effects makes it possible to obtain vulcanizates with an optimal set of technological and operational properties.","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":"74255787","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-2023-6-17-23
D. Panov
Samples of the “silver – polymer” composite were obtained by the matrix synthesis method. Track membranes made of polyethylene terephthalate with pores of different diameters and with different concentrations were used as a matrix. The matrix pores were filled by electrochemical deposition. The structure and mechanical properties of this composite, which is a porous polymer matrix with nano- and microwires of silver deposited into pores, have been studied. Mechanical properties were determined experimentally by stretching the samples. Using the method of scanning electron microscopy, it was found that the length of nano- and microwires filling the pores of the PET matrix is not the same in the same sample, while frequent mutual intersection of the wires was observed, the concentrations of nano- and microwires were determined from SEM microimages. The crossing probability and the number of crossing nano- and microwires were calculated using a previously developed technique based on the single bond method. It is shown that the mechanical properties of the metal-polymer composite are significantly affected by the number of wire intersections and, at the same concentration of wires, their diameter.
{"title":"Study of the mechanical properties and structure of the “silver – polyethylene terephthalate” composite","authors":"D. Panov","doi":"10.30791/1028-978x-2023-6-17-23","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-6-17-23","url":null,"abstract":"Samples of the “silver – polymer” composite were obtained by the matrix synthesis method. Track membranes made of polyethylene terephthalate with pores of different diameters and with different concentrations were used as a matrix. The matrix pores were filled by electrochemical deposition. The structure and mechanical properties of this composite, which is a porous polymer matrix with nano- and microwires of silver deposited into pores, have been studied. Mechanical properties were determined experimentally by stretching the samples. Using the method of scanning electron microscopy, it was found that the length of nano- and microwires filling the pores of the PET matrix is not the same in the same sample, while frequent mutual intersection of the wires was observed, the concentrations of nano- and microwires were determined from SEM microimages. The crossing probability and the number of crossing nano- and microwires were calculated using a previously developed technique based on the single bond method. It is shown that the mechanical properties of the metal-polymer composite are significantly affected by the number of wire intersections and, at the same concentration of wires, their diameter.","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":"74346198","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-2023-7-5-9
Y. Levinsky, E. Vershinina, M. Alymov
Up to now Co – Mg alloys have not been studied in detail. The information available in the literature refers to the study of changes in the Co – Mg system in the composition-temperature coordinates. However, this does not take into account the significant difference in vapor pressure values of Mg and Co in the alloy, which significantly reduces the accuracy of the results obtained. It is proposed to analyze the Co – Mg system in the coordinates composition-temperature-pressure. The following results have been obtained and presented in the article: a detailed description of the Mg – Co system diagram in the pressure-temperature coordinates, the projections of the three-phase equilibrium lines, some isobaric and isothermal sections of the p – T – X state diagram of Mg – Co system, Mg – Co state diagram in coordinates temperature – partial pressure Mg. The results obtained in this work can be successfully used in the development of ternary and more alloys containing cobalt and magnesium.
{"title":"P – T – X diagram of the Co – Mg system","authors":"Y. Levinsky, E. Vershinina, M. Alymov","doi":"10.30791/1028-978x-2023-7-5-9","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-7-5-9","url":null,"abstract":"Up to now Co – Mg alloys have not been studied in detail. The information available in the literature refers to the study of changes in the Co – Mg system in the composition-temperature coordinates. However, this does not take into account the significant difference in vapor pressure values of Mg and Co in the alloy, which significantly reduces the accuracy of the results obtained. It is proposed to analyze the Co – Mg system in the coordinates composition-temperature-pressure. The following results have been obtained and presented in the article: a detailed description of the Mg – Co system diagram in the pressure-temperature coordinates, the projections of the three-phase equilibrium lines, some isobaric and isothermal sections of the p – T – X state diagram of Mg – Co system, Mg – Co state diagram in coordinates temperature – partial pressure Mg. The results obtained in this work can be successfully used in the development of ternary and more alloys containing cobalt and magnesium.","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":"82578494","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-2023-4-50-59
N. V. Shadrinov, K. P. Antoev
An opportunity of development of electrically conductive rubber based on industrially produced tyre regenerate RShT-4 and Reg-1, obtained in laboratory conditions, with electrically conductive carbon fillers is shown. OMCARB CH85 carbon black (CB) produced by “Omsktehuglerod” Ltd. and Tenax-e HTS-45 carbon fibres (CF) produced by Toho Tenax America were used as electrically conductive fillers. Curing and rheometric properties of regenerates with different content of Santogard PVI and electroconductive fillers have been investigated. The study of physical and mechanical properties of regenerates has shown that introduction and increase of electroconductive CB and CF content in Reg-1 and RShT-4 leads to gradual reduction of elongation at break and increase in tensile strength and Shore A hardness, which is evidence of reinforcing effect of fillers. The effect of tensoresistance in the obtained regenerates depending on the content of electroconductive fillers is investigated. It is shown that addition of electroconductive CB to Reg-1 and RSHT-4 gives electroconductivity and tensoresistivity, that is, decrease of resistance in compression. Addition of CF leads to the opposite effect - increase of electrical resistance in compression. The possible mechanisms for the manifistation of tensoresistance at introduction of electroconductive CB and decrease of electroconductivity at introduction of CF are offered.
{"title":"Investigation of the influence of carbon fillers on the manifestation of the effect of tensoresistivity in tire regenerates","authors":"N. V. Shadrinov, K. P. Antoev","doi":"10.30791/1028-978x-2023-4-50-59","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-4-50-59","url":null,"abstract":"An opportunity of development of electrically conductive rubber based on industrially produced tyre regenerate RShT-4 and Reg-1, obtained in laboratory conditions, with electrically conductive carbon fillers is shown. OMCARB CH85 carbon black (CB) produced by “Omsktehuglerod” Ltd. and Tenax-e HTS-45 carbon fibres (CF) produced by Toho Tenax America were used as electrically conductive fillers. Curing and rheometric properties of regenerates with different content of Santogard PVI and electroconductive fillers have been investigated. The study of physical and mechanical properties of regenerates has shown that introduction and increase of electroconductive CB and CF content in Reg-1 and RShT-4 leads to gradual reduction of elongation at break and increase in tensile strength and Shore A hardness, which is evidence of reinforcing effect of fillers. The effect of tensoresistance in the obtained regenerates depending on the content of electroconductive fillers is investigated. It is shown that addition of electroconductive CB to Reg-1 and RSHT-4 gives electroconductivity and tensoresistivity, that is, decrease of resistance in compression. Addition of CF leads to the opposite effect - increase of electrical resistance in compression. The possible mechanisms for the manifistation of tensoresistance at introduction of electroconductive CB and decrease of electroconductivity at introduction of CF are offered.","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":"81923375","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-2023-5-35-45
N. V. Shchipalkina, S. V. Pshenov, V. Chursin, D. S. Sadilo, E. Kolesnikov
Сharacteristics of spherical powders of (Mo,Nb) and (Nb,Mo) alloys prepared by spark erosion technique are described. Two regimes (U = 24 V, I = 10 A and U = 24 V, I = 20 A in distilled water) were chosen for powder preparation. The pyrolysis of dielectric liquid during spark erosion leads to the formation of stable oxides NbO and NbO2 as thin crusts and spherical inclusions from 10 nm to 10 µm in powder particles. The largest deviations from electrode compositions (from 3 to 7 wt.% Nb) are inherent to Mo alloys with 9 and 10 wt.% of Nb. The number of NbO and to a lesser extent NbO2 inclusions in spherical powder increase with increasing of Nb content in alloy, but only in series of (Mo,Nb) samples. Such regularity is not observed for (Nb,Mo) series. Decrease of current value results the change of granulometric compositions of spherical powders. The main fraction of powders at I = 20 A is 40-80 µm and I = 10 A is 20-50 µm.
{"title":"Features of spark erosion fine Mo and Nb alloys powders","authors":"N. V. Shchipalkina, S. V. Pshenov, V. Chursin, D. S. Sadilo, E. Kolesnikov","doi":"10.30791/1028-978x-2023-5-35-45","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-5-35-45","url":null,"abstract":"Сharacteristics of spherical powders of (Mo,Nb) and (Nb,Mo) alloys prepared by spark erosion technique are described. Two regimes (U = 24 V, I = 10 A and U = 24 V, I = 20 A in distilled water) were chosen for powder preparation. The pyrolysis of dielectric liquid during spark erosion leads to the formation of stable oxides NbO and NbO2 as thin crusts and spherical inclusions from 10 nm to 10 µm in powder particles. The largest deviations from electrode compositions (from 3 to 7 wt.% Nb) are inherent to Mo alloys with 9 and 10 wt.% of Nb. The number of NbO and to a lesser extent NbO2 inclusions in spherical powder increase with increasing of Nb content in alloy, but only in series of (Mo,Nb) samples. Such regularity is not observed for (Nb,Mo) series. Decrease of current value results the change of granulometric compositions of spherical powders. The main fraction of powders at I = 20 A is 40-80 µm and I = 10 A is 20-50 µm.","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":"80207977","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-2023-5-46-55
V. A. Korolev, A. Sidorov, I. Mikhailov, A. A. Matsaev, E. Zemlyakov, P. Kuznetsov, D. A. Nameev
The main advantages of direct laser deposition (DLD) of large-sized products are discussed on the example of the internal core baffle of a pressurized water reactor (VVER core baffle). The problem of product damage during operation as a part of reactor was considered. Powder materials of stainless steel with Russian grades 08Cr18Ni10Ti and 10Cr16Ni25MoTi were produced to develop the DLD process. Optimization of the core baffle design was carried out to improve operating reliability. Samples and fragments of the core baffle were manufactured by DLD method with complex research and tests. The concept of an experimental DLD unit for large-scale parts were developed.
{"title":"Development of direct laser deposition technology for large-scale products of nuclear power engineering","authors":"V. A. Korolev, A. Sidorov, I. Mikhailov, A. A. Matsaev, E. Zemlyakov, P. Kuznetsov, D. A. Nameev","doi":"10.30791/1028-978x-2023-5-46-55","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-5-46-55","url":null,"abstract":"The main advantages of direct laser deposition (DLD) of large-sized products are discussed on the example of the internal core baffle of a pressurized water reactor (VVER core baffle). The problem of product damage during operation as a part of reactor was considered. Powder materials of stainless steel with Russian grades 08Cr18Ni10Ti and 10Cr16Ni25MoTi were produced to develop the DLD process. Optimization of the core baffle design was carried out to improve operating reliability. Samples and fragments of the core baffle were manufactured by DLD method with complex research and tests. The concept of an experimental DLD unit for large-scale parts were developed.","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":"77523413","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-2023-2-54-61
M. Piskarev, А. V. Zinoviev, A. Gilman, E. Skryleva, B. Senatulin, A. Kuznetsov, A. Gatin
Using X-ray photoelectron spectroscopy, the change in the chemical composition of the polyketon films surface as a result of treatment by the low-pressure direct current discharge was studied. The films were placed at the anode and cathode, and filtered atmospheric air was used as the working gas. The formation of a significant amount of oxygen-containing groups on the polymer surface was shown. Using atomic force microscopy, it was found that plasma treatment leads to a significant increase in the surface roughness of the films. Such changes improve the contact and adhesion properties of polyketon films.
{"title":"Effect of low-temperature plasma treatment on polyketon films: changes in the chemical structure and surface morphology","authors":"M. Piskarev, А. V. Zinoviev, A. Gilman, E. Skryleva, B. Senatulin, A. Kuznetsov, A. Gatin","doi":"10.30791/1028-978x-2023-2-54-61","DOIUrl":"https://doi.org/10.30791/1028-978x-2023-2-54-61","url":null,"abstract":"Using X-ray photoelectron spectroscopy, the change in the chemical composition of the polyketon films surface as a result of treatment by the low-pressure direct current discharge was studied. The films were placed at the anode and cathode, and filtered atmospheric air was used as the working gas. The formation of a significant amount of oxygen-containing groups on the polymer surface was shown. Using atomic force microscopy, it was found that plasma treatment leads to a significant increase in the surface roughness of the films. Such changes improve the contact and adhesion properties of polyketon films.","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":"73772352","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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