Pub Date : 1900-01-01DOI: 10.30791/0015-3214-2021-2-80-85
Z. I. Iskenderova
In this work, a comparative study of the kinetics of changes in the pH indicator, the formation of H2O2 and CO2 depending on the absorbed dose at the radiolysis of TCB containing transformer oil in the presence and without nano-γ-Al2O3 under the action of γ radiation was carried out. During radiolysis of both systems (TСB + transformer oil and TСB + transformer oil + 0.1 g of nano-γ-Al2O3), the radiation-chemical yield of CO2 decreases with an increase in the initial concentration of TCB, although at the presence of nano-particles, the values of the radiation-chemical riels of CO2 become less. Unlike CO2, the radiation-chemical yields of H2O2 increase with an increase in the initial concentration of TCB, but their values are less in the presence of nano-γ-Al2O3. The results obtained are explained by the reactions of active particles, radiolysis of the main components of transformer oil, such as hydrogen atoms and hydrocarbon radicals with TCB and dissolved oxygen molecules. In addition, there is a transfer of electronic excitation energy from alkane and cycloalkane molecules to aromatic hydrocarbon molecules. The effect of nano-γ-Al2O3 on the radiolysis of the mixture is discussed on the basis of the reaction of electron and hole centers with the molecules of the components of the irradiated mixture.
{"title":"Radiolysis of transformer oil in presence of trichlorbenzen and nano-γ-Al2O3","authors":"Z. I. Iskenderova","doi":"10.30791/0015-3214-2021-2-80-85","DOIUrl":"https://doi.org/10.30791/0015-3214-2021-2-80-85","url":null,"abstract":"In this work, a comparative study of the kinetics of changes in the pH indicator, the formation of H2O2 and CO2 depending on the absorbed dose at the radiolysis of TCB containing transformer oil in the presence and without nano-γ-Al2O3 under the action of γ radiation was carried out. During radiolysis of both systems (TСB + transformer oil and TСB + transformer oil + 0.1 g of nano-γ-Al2O3), the radiation-chemical yield of CO2 decreases with an increase in the initial concentration of TCB, although at the presence of nano-particles, the values of the radiation-chemical riels of CO2 become less. Unlike CO2, the radiation-chemical yields of H2O2 increase with an increase in the initial concentration of TCB, but their values are less in the presence of nano-γ-Al2O3. The results obtained are explained by the reactions of active particles, radiolysis of the main components of transformer oil, such as hydrogen atoms and hydrocarbon radicals with TCB and dissolved oxygen molecules. In addition, there is a transfer of electronic excitation energy from alkane and cycloalkane molecules to aromatic hydrocarbon molecules. The effect of nano-γ-Al2O3 on the radiolysis of the mixture is discussed on the basis of the reaction of electron and hole centers with the molecules of the components of the irradiated mixture.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"37 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":"124031420","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: 10.30791/0015-3214-2021-3-24-29
Y. Kashlev, S. A. Maslyaev
A vacancy in a one-dimensional lattice is considered as a vacant site in a one-dimensional chain of atoms. The energy model of this system is a double potential well with two levels. Based on the relations of nonequilibrium statistical mechanics, including the Kubo formula for the transport coefficient, the frequency of vacancy jumps is calculated. In this case, two factors of the system perturbation are taken into account: lattice deformation associated with the formation of an empty site, and phonon scattering by mass fluctuations in the chain. An analysis of two high-temperature jumps is given. First, the classical limit of vacancy motion under weak coupling conditions is considered for small values of the gradient of the interaction potential of the defect with the chain. In the classical case, the transition of an atom adjacent to a vacancy occurs through a quasy-stationary excited state. Secondly, a jump under tight binding conditions, when the motion of a neighboring atom occurs through a quasistationary state of finite width, and therefore having a finite lifetime.
{"title":"Non-coherent diffusion of a vacancy in a one-dimensional lattice in the quasiclassical approximation","authors":"Y. Kashlev, S. A. Maslyaev","doi":"10.30791/0015-3214-2021-3-24-29","DOIUrl":"https://doi.org/10.30791/0015-3214-2021-3-24-29","url":null,"abstract":"A vacancy in a one-dimensional lattice is considered as a vacant site in a one-dimensional chain of atoms. The energy model of this system is a double potential well with two levels. Based on the relations of nonequilibrium statistical mechanics, including the Kubo formula for the transport coefficient, the frequency of vacancy jumps is calculated. In this case, two factors of the system perturbation are taken into account: lattice deformation associated with the formation of an empty site, and phonon scattering by mass fluctuations in the chain. An analysis of two high-temperature jumps is given. First, the classical limit of vacancy motion under weak coupling conditions is considered for small values of the gradient of the interaction potential of the defect with the chain. In the classical case, the transition of an atom adjacent to a vacancy occurs through a quasy-stationary excited state. Secondly, a jump under tight binding conditions, when the motion of a neighboring atom occurs through a quasistationary state of finite width, and therefore having a finite lifetime.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"2015 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":"127781975","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: 10.30791/0015-3214-2021-4-25-30
O. Berdnik, P. Y. Kikin, V. Perevezentsev, E. Razov, E. Rusin, I. Tsareva
The regularities of changes in the structure and phase composition of the thermal protective aluminide-nickel coating (Ni — 45 %; Al — 14 %; Co — 22 %; Cr — 18.9 %; Fe — 0.15 %; Nb — 0.14 %; Y — 0.09 %; Ca — 0.06 %; Mn — 0.01 %; C — 0.15 %; Si — 0.15 %; S — 0.006 %) after exposure to short-term pulsed heat fluxes of various power, created by the radiation of a pulse-periodic laser LRS-150A with a radiation wavelength λ = 1.06 µm and a pulse duration τ = 12·10–3 s. The radiation energy was E = 5, 10, and 15 J. Microstructural analysis and the elemental composition of the resulting coating were carried out as well as analysis of the phase composition. X-ray microanalysis of the coating was also carried out. In the initial state and after irradiation of the coating with a heat flux of power P = 7·103 W/cm2, light microregions are observed in the micrographs of the surface. These regions do not have clearly defined external boundaries and consist of the NiAl phase and a small amount of the Ni3Al phase with the presence of inclusions of particles containing a solid solution of Ni – Co – Cr. After irradiation of the coating with heat fluxes of higher power (P = 1.7·104 W/cm2 and P = 2.2·104 W/cm2), large convex formations appeared on its surface, consisting mainly of Ni3Al and NiAl phases. On micrographs of the surface, they appear as white areas with well-defined outer boundaries. The content of the Ni3Al phase in them in comparison with the initial state increased, and the content of the NiAl phase decreased, while the particles of inclusions of Ni, Co, and Cr disappeared. It can be assumed that an increase in the Ni3Al content is associated with the dissolution of particles of a solid solution of Ni – Co and Cr in the melt and the subsequent diffusion of nickel into the NiAl phase. When exposed to a heat flux of power P = 2.2·104 W/cm2, microcracks appear on the areas of the coating surface covered with aluminum oxide.
{"title":"Changes in the structure of a thermal protective aluminum-nickel coating under the influence of a single thermal laser pulse","authors":"O. Berdnik, P. Y. Kikin, V. Perevezentsev, E. Razov, E. Rusin, I. Tsareva","doi":"10.30791/0015-3214-2021-4-25-30","DOIUrl":"https://doi.org/10.30791/0015-3214-2021-4-25-30","url":null,"abstract":"The regularities of changes in the structure and phase composition of the thermal protective aluminide-nickel coating (Ni — 45 %; Al — 14 %; Co — 22 %; Cr — 18.9 %; Fe — 0.15 %; Nb — 0.14 %; Y — 0.09 %; Ca — 0.06 %; Mn — 0.01 %; C — 0.15 %; Si — 0.15 %; S — 0.006 %) after exposure to short-term pulsed heat fluxes of various power, created by the radiation of a pulse-periodic laser LRS-150A with a radiation wavelength λ = 1.06 µm and a pulse duration τ = 12·10–3 s. The radiation energy was E = 5, 10, and 15 J. Microstructural analysis and the elemental composition of the resulting coating were carried out as well as analysis of the phase composition. X-ray microanalysis of the coating was also carried out. In the initial state and after irradiation of the coating with a heat flux of power P = 7·103 W/cm2, light microregions are observed in the micrographs of the surface. These regions do not have clearly defined external boundaries and consist of the NiAl phase and a small amount of the Ni3Al phase with the presence of inclusions of particles containing a solid solution of Ni – Co – Cr. After irradiation of the coating with heat fluxes of higher power (P = 1.7·104 W/cm2 and P = 2.2·104 W/cm2), large convex formations appeared on its surface, consisting mainly of Ni3Al and NiAl phases. On micrographs of the surface, they appear as white areas with well-defined outer boundaries. The content of the Ni3Al phase in them in comparison with the initial state increased, and the content of the NiAl phase decreased, while the particles of inclusions of Ni, Co, and Cr disappeared. It can be assumed that an increase in the Ni3Al content is associated with the dissolution of particles of a solid solution of Ni – Co and Cr in the melt and the subsequent diffusion of nickel into the NiAl phase. When exposed to a heat flux of power P = 2.2·104 W/cm2, microcracks appear on the areas of the coating surface covered with aluminum oxide.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"1 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":"130306073","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: 10.30791/0015-3214-2019-5-21-35
E. Voronina, L. Novikov, Y. Mankelevich
{"title":"Simulation of plasma particle impacts on 2D materials","authors":"E. Voronina, L. Novikov, Y. Mankelevich","doi":"10.30791/0015-3214-2019-5-21-35","DOIUrl":"https://doi.org/10.30791/0015-3214-2019-5-21-35","url":null,"abstract":"","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"1 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":"130284816","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: 10.30791/0015-3214-2020-6-69-74
V. Kudinov, I. Krylov, N. Korneeva
The low-velosity impact properties and failure mechanisms of ultra-high molecular weight polyethylene (UHMWPE) fiber (Dyneema®SK-75) and a composite material (CM) based on it with the rigid and flexible matrices were investigated by the “Impact Break” (IB) method. A fundamental difference in deformation behavior and failure mechanisms upon impact on the UHMWPE-fiber and on the CM based on this fiber has been investigated experimentally. It is shown that impact has a little effect on the properties of UHMWPE-fiber, since it is an isotropic material. It has been established that upon impact, the properties of a fiber without a matrix were significantly higher than the properties of CM based on it. Impact action stimulates the interaction between CM components (fibers and matrix). Mechanism of stepwise deformation of anisotropic CM is occurred, which begins from the first moment of impact and ends with the destruction of the CM. A “stairway of deformation” behavior is observed in anisotropic materials. Stepwise deformation is the main form of deformation and the basic mechanism of failure of anisotropic composite materials upon impact.
{"title":"Impact action on fiber and composite material based on it","authors":"V. Kudinov, I. Krylov, N. Korneeva","doi":"10.30791/0015-3214-2020-6-69-74","DOIUrl":"https://doi.org/10.30791/0015-3214-2020-6-69-74","url":null,"abstract":"The low-velosity impact properties and failure mechanisms of ultra-high molecular weight polyethylene (UHMWPE) fiber (Dyneema®SK-75) and a composite material (CM) based on it with the rigid and flexible matrices were investigated by the “Impact Break” (IB) method. A fundamental difference in deformation behavior and failure mechanisms upon impact on the UHMWPE-fiber and on the CM based on this fiber has been investigated experimentally. It is shown that impact has a little effect on the properties of UHMWPE-fiber, since it is an isotropic material. It has been established that upon impact, the properties of a fiber without a matrix were significantly higher than the properties of CM based on it. Impact action stimulates the interaction between CM components (fibers and matrix). Mechanism of stepwise deformation of anisotropic CM is occurred, which begins from the first moment of impact and ends with the destruction of the CM. A “stairway of deformation” behavior is observed in anisotropic materials. Stepwise deformation is the main form of deformation and the basic mechanism of failure of anisotropic composite materials upon impact.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"9 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":"116766532","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: 10.30791/0015-3214-2019-2-5-13
O. Laput, I. Kurzina, I. Vasenina
{"title":"Effect of Ag2+ and C+ ion implantation on the surface physicochemical properties of polylactic acid, hydroxyapatite and composite materials based on them","authors":"O. Laput, I. Kurzina, I. Vasenina","doi":"10.30791/0015-3214-2019-2-5-13","DOIUrl":"https://doi.org/10.30791/0015-3214-2019-2-5-13","url":null,"abstract":"","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"19 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":"126909749","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: 10.30791/0015-3214-2022-2-13-22
A. M. Kruchinin, M. Pogrebisskiy, E. Ryazanova, A. Chursin
The method of universal arc characteristics developed for calculating the electrical and thermal characteristics of the cylindrical part of the Mecker model column allows simple algebraic methods to calculate the characteristics of the arc column at a distance from the cathode and, thereby, to concretize the mathematical model of Mecker. The proven conservativeness of the arc as a result of the formation of a spatial layer with increased volumetric viscosity on the surface of the column allows, in accordance with the provisions of the boundary layer theory, to apply a boundary condition of the third kind to the surface of the cylindrical part of the arc column. The method of universal arc characteristics also helps to link the boundary value of the linear heat flux density on the surface of the cylindrical part of the column with the temperature profile of the column and, thereby, to specify the dependence of the electrical, geometric and thermal characteristics of the column plasma on the conditions of arc heat exchange in the working space of the installation with electric arc heating. The proposed method makes it possible, based only on the external voltage characteristics of the arc, to identify the Mecker heat exchange model and calculate by a simple algebraic method the structure and values of the heat fluxes generated by the arc during heat exchange with the plasma torch gas jet in the melting space of the plasma arc furnace. Examples of arc characteristics are given when working on different gases for different stages of melting — at the beginning of melting and during the melting of the charge.
{"title":"Calculation of rational modes of plasma torches for plasma arc furnaces","authors":"A. M. Kruchinin, M. Pogrebisskiy, E. Ryazanova, A. Chursin","doi":"10.30791/0015-3214-2022-2-13-22","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-2-13-22","url":null,"abstract":"The method of universal arc characteristics developed for calculating the electrical and thermal characteristics of the cylindrical part of the Mecker model column allows simple algebraic methods to calculate the characteristics of the arc column at a distance from the cathode and, thereby, to concretize the mathematical model of Mecker. The proven conservativeness of the arc as a result of the formation of a spatial layer with increased volumetric viscosity on the surface of the column allows, in accordance with the provisions of the boundary layer theory, to apply a boundary condition of the third kind to the surface of the cylindrical part of the arc column. The method of universal arc characteristics also helps to link the boundary value of the linear heat flux density on the surface of the cylindrical part of the column with the temperature profile of the column and, thereby, to specify the dependence of the electrical, geometric and thermal characteristics of the column plasma on the conditions of arc heat exchange in the working space of the installation with electric arc heating. The proposed method makes it possible, based only on the external voltage characteristics of the arc, to identify the Mecker heat exchange model and calculate by a simple algebraic method the structure and values of the heat fluxes generated by the arc during heat exchange with the plasma torch gas jet in the melting space of the plasma arc furnace. Examples of arc characteristics are given when working on different gases for different stages of melting — at the beginning of melting and during the melting of the charge.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"129 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":"124420227","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: 10.30791/0015-3214-2022-6-26-32
T. Obolkina, M. Goldberg, S. Smirnov, O. Antonova, D. A. Utkin, D. Khairutdinova, A. Konovalov, G. Kochanov, S. Barinov, V. Komlev
In this article, we studied the influence of Mn2+ on the properties (on the phase composition, porosity, microstructure, three-point bending strength and microhardness) and sintering of the ZrO2 – Al2O3 – SiO2 composite ceramic materials. The ZrO2 – Al2O3 – SiO2 ceramic powder containing 2,5 wt.% Al2O3 and 0,5 wt.% SiO2 with 24,7 m2/g specific area was synthesized through co-precipitation method. Three concentrations of Mn2+ are considered: 0.25, 0.50 and 0.75 mol%. The introduction of Mn2+ leads to a significant increase in mechanical properties. The samples sintered at 1250 and 1300 °C for 2 hours. The highest value of strength at three-point bending 761 ± 36 MPa and microhardness 9.5 ± 0.5 GPa was characterized by the material of the composition ZrO2 – Al2O3 – SiO2 containing 0.75 mol.% Mn2+ sintered at 1300 °С. The crack resistance of this material was 7.0 MPa·m1/2. At the same time, the highest values of crack resistance 9.3 ± 0.5 MPa·m1/2 were shown by materials of the composition ZrO2 – Al2O3 – SiO2 containing 0.75 mol. % Mn2+ sintered at 1250 °C.
{"title":"The effect of Mn2+ on the microstructure and mechanical properties of ZrO2 – Al2O3 – SiO2 ceramic materials","authors":"T. Obolkina, M. Goldberg, S. Smirnov, O. Antonova, D. A. Utkin, D. Khairutdinova, A. Konovalov, G. Kochanov, S. Barinov, V. Komlev","doi":"10.30791/0015-3214-2022-6-26-32","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-6-26-32","url":null,"abstract":"In this article, we studied the influence of Mn2+ on the properties (on the phase composition, porosity, microstructure, three-point bending strength and microhardness) and sintering of the ZrO2 – Al2O3 – SiO2 composite ceramic materials. The ZrO2 – Al2O3 – SiO2 ceramic powder containing 2,5 wt.% Al2O3 and 0,5 wt.% SiO2 with 24,7 m2/g specific area was synthesized through co-precipitation method. Three concentrations of Mn2+ are considered: 0.25, 0.50 and 0.75 mol%. The introduction of Mn2+ leads to a significant increase in mechanical properties. The samples sintered at 1250 and 1300 °C for 2 hours. The highest value of strength at three-point bending 761 ± 36 MPa and microhardness 9.5 ± 0.5 GPa was characterized by the material of the composition ZrO2 – Al2O3 – SiO2 containing 0.75 mol.% Mn2+ sintered at 1300 °С. The crack resistance of this material was 7.0 MPa·m1/2. At the same time, the highest values of crack resistance 9.3 ± 0.5 MPa·m1/2 were shown by materials of the composition ZrO2 – Al2O3 – SiO2 containing 0.75 mol. % Mn2+ sintered at 1250 °C.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"5 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":"121491541","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: 10.30791/0015-3214-2022-6-5-10
A. Ligachev, M. Zhidkov, Y. Kolobov, G. Potemkin, M. V. Lukahova, G. Remnev, S. Pavlov, G. E. Tarbokov
The tungsten surface was processed by high power pulsed ion beam at the TEMP accelerator (Cn+ ions, accelerating voltage 200 ± 10 kV, energy density of a single pulse 2.6 – 3.0 J/cm2). Changes in the relief and structure of the surface of tungsten samples were studied by scanning electron microscopy. After treatment with a powerful pulsed ion beam (MIIP), defects in the form of craters form on the surface of tungsten. The number of craters decreases with an increase in the number of impact pulses. After exposure to 3 pulses, microcraters are forms in the surface layer along the grain boundaries. After 10 pulses, there are practically no cracks on the irradiated surface. An increase in the number of pulses leads to the formation of a more equiaxed ultrafine-grained structure in the near-surface layer of tungsten.
{"title":"The effect of a high-power pulsed ion beam on the surface topography of the tungsten","authors":"A. Ligachev, M. Zhidkov, Y. Kolobov, G. Potemkin, M. V. Lukahova, G. Remnev, S. Pavlov, G. E. Tarbokov","doi":"10.30791/0015-3214-2022-6-5-10","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-6-5-10","url":null,"abstract":"The tungsten surface was processed by high power pulsed ion beam at the TEMP accelerator (Cn+ ions, accelerating voltage 200 ± 10 kV, energy density of a single pulse 2.6 – 3.0 J/cm2). Changes in the relief and structure of the surface of tungsten samples were studied by scanning electron microscopy. After treatment with a powerful pulsed ion beam (MIIP), defects in the form of craters form on the surface of tungsten. The number of craters decreases with an increase in the number of impact pulses. After exposure to 3 pulses, microcraters are forms in the surface layer along the grain boundaries. After 10 pulses, there are practically no cracks on the irradiated surface. An increase in the number of pulses leads to the formation of a more equiaxed ultrafine-grained structure in the near-surface layer of tungsten.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"144 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":"121520893","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: 10.30791/0015-3214-2022-3-54-66
M. Gryaznov, A. Samokhin, V. Chuvildeev, A. Fadeev, N. Alekseev, S. Shotin, A. A. Dorofeev
The powder of 93 W – 4.9 Ni – 2.1 Fe (VNZh-93) pseudo-alloy with a spherical particle shape in the size range of 15 – 50 μm with a grain size of 0.5 – 3 μm was obtained using plasma chemical synthesis, granulation and spheroidization technologies. The possibility of using spheroidized powder VNZh-93 in additive 3D-printing is demonstrated. Studies of the physical and mechanical characteristics and microstructure of VNZh-93 test samples made using the selective laser melting technology (SLM) have been carried out. It is shown that the parameters of the SLM significantly affect the formation of the microstructure of test samples. It is possible to form a homogeneous equiaxed microstructure with an average grain size of about 1 micron using optimal SLM modes. It is shown that maximum density and Vickers hardness of VNZh-93 obtained in optimal SLM modes are 16.8 g/cm3 and 480 HV, respectively. These values are not inferior to the values for VNZh-93 samples obtained using traditional liquid-phase sintering technology. At the same time, the main problem of selective laser melting of VNZh-93 powder is the heterogeneity of the bulk samples microstructure and the formation of microcracks and micropores in their structure.
采用等离子体化学合成、造粒和球化技术制备了93 W - 4.9 Ni - 2.1 Fe (VNZh-93)伪合金粉末，粉末尺寸为15 ~ 50 μm，晶粒尺寸为0.5 ~ 3 μm。论证了球化粉末VNZh-93用于增材3d打印的可能性。采用选择性激光熔化技术(SLM)对VNZh-93试样的物理力学特性和显微组织进行了研究。结果表明，SLM的参数对试样微观结构的形成有显著影响。利用最佳SLM模式可以形成平均晶粒尺寸约为1微米的均匀等轴微观结构。结果表明，在最佳SLM模式下，VNZh-93的最大密度和维氏硬度分别为16.8 g/cm3和480 HV。这些值不低于用传统液相烧结技术得到的VNZh-93样品的值。同时，VNZh-93粉末选择性激光熔化的主要问题是试样组织的不均匀性和组织中微裂纹和微孔的形成。
{"title":"Obtaining composite 93 W – 4.9 Ni – 2.1 Fe powder with a spherical particle and investigating the possibility of its use in selective laser melting","authors":"M. Gryaznov, A. Samokhin, V. Chuvildeev, A. Fadeev, N. Alekseev, S. Shotin, A. A. Dorofeev","doi":"10.30791/0015-3214-2022-3-54-66","DOIUrl":"https://doi.org/10.30791/0015-3214-2022-3-54-66","url":null,"abstract":"The powder of 93 W – 4.9 Ni – 2.1 Fe (VNZh-93) pseudo-alloy with a spherical particle shape in the size range of 15 – 50 μm with a grain size of 0.5 – 3 μm was obtained using plasma chemical synthesis, granulation and spheroidization technologies. The possibility of using spheroidized powder VNZh-93 in additive 3D-printing is demonstrated. Studies of the physical and mechanical characteristics and microstructure of VNZh-93 test samples made using the selective laser melting technology (SLM) have been carried out. It is shown that the parameters of the SLM significantly affect the formation of the microstructure of test samples. It is possible to form a homogeneous equiaxed microstructure with an average grain size of about 1 micron using optimal SLM modes. It is shown that maximum density and Vickers hardness of VNZh-93 obtained in optimal SLM modes are 16.8 g/cm3 and 480 HV, respectively. These values are not inferior to the values for VNZh-93 samples obtained using traditional liquid-phase sintering technology. At the same time, the main problem of selective laser melting of VNZh-93 powder is the heterogeneity of the bulk samples microstructure and the formation of microcracks and micropores in their structure.","PeriodicalId":366423,"journal":{"name":"Physics and Chemistry of Materials Treatment","volume":"44 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":"121530324","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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