284 results on '"Yu, R"'
Search Results
2. Refractory Concrete Based on High-Alumina Cement and Clinker Filler
- Author
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T. V. Kuznetsova, Yu. R. Krivoborodov, and S. V. Samchenko
- Subjects
Cement ,Materials science ,Aggregate (composite) ,Metallurgy ,engineering.material ,Clinker (cement) ,Compressive strength ,Filler (materials) ,Materials Chemistry ,Ceramics and Composites ,engineering ,Hardening (metallurgy) ,Refractory (planetary science) ,Shrinkage - Abstract
Results of studying of the possibility of using clinker as a filler for producing refractory concrete based on high-alumina cement are presented. Clinker is used for cement and aggregate production. The main properties of clinker as an aggregate are studied. On the basis of high-alumina cement and its clinker a refractory concrete composition is developed that has compressive strength with normal hardening of 50 – 55 MPa, shrinkage of 0,2%, and a heat resistance of more than 35 thermal cycles (1300°C – water). Special attention is devoted to the contact zone formed between filler and cement. Refractory concrete pertains to class 16 and is recommended for lining heating units in the chemical industry.
- Published
- 2021
3. In vivo assessment of the biocompatible properties of resorbable porous materials for pleural implantation
- Author
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Yu. D. Zagoskin, I. A. Vasileva, K. V. Tokaev, V. I. Sevastianov, K. I. Lukanina, Sergey N. Chvalun, A. S. Bikbaev, T. K. Tokaev, Yu. R. Zyuza, T. E. Grigoriev, and V. K. Tokaev
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Transplantation ,Materials science ,Lung ,Biocompatibility ,02 engineering and technology ,Pleural cavity ,021001 nanoscience & nanotechnology ,Biocompatible material ,Resorption ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine.anatomical_structure ,chemistry ,In vivo ,Polycaprolactone ,medicine ,Immunology and Allergy ,0210 nano-technology ,Porous medium ,030217 neurology & neurosurgery ,Biomedical engineering - Abstract
Correcting the pleural cavity space or filling large residual cavities (up to 500-700 cm3), arising as a result of extensive combined resections of the lung or extrapleural pneumolysis in tuberculosis and other lung diseases, still remains a challenging issue. The surgical methods used to correct the pleural cavity space are traumatic in nature. Moreover, various biological and synthetic materials used are not effective enough. Objective: to conduct an in vivo study of the biocompatible properties of laboratory samples of porous materials based on polylactide (PLA) and polycaprolactone (PCL) as potential materials for pleural implants development, as part of the general problem of developing a resorbable porous implant for intra- and extrapleural implantation and in situ formation of a «biological filling» to correct the volume of the pleural cavity. Materials and methods. In vivo subcutaneous implantation was performed in Wistar rats. The experiment involved the following samples: No. 1 - 3.0%; No. 2 - 4.0%; No. 3 - 1.7%. The ratio of the polymers in the solution was, respectively: 3/1, 1/3 and 1/1 PLA/PCL. Highly porous implants were obtained by lyophilization. The porosity of the samples ranged from 96.0% to 98.3%. The Young's modulus was from 100 to 1800 kPa. In the control group, a Mentor silicone implant shell was used. The explantation time was 1, 2, 3, 4, 5, 8, 12, 14 weeks. Histological, histochemical and immunohistochemical studies of explants and surrounding local tissues were conducted. Results. Reaction of local tissues to the implantation of three types of samples of different composition from PLA/PCL, accompanied by material resorption processes, replacement by fibrous tissue, vascularization and encapsulation, without perifocal inflammation and reactive changes, indicates the biocompatibility of the materials studied. In control samples with silicone implant, a long-lasting perifocal reaction from eosinophilic leukocytes was revealed, which prevents us from excluding the possibility of an allergic reaction to the implant material in the surrounding tissues. Conclusion. In vivo experiments on the small animals show the biosafety and high biocompatibility of laboratory samples of bioresorbable highly porous matrices based on polylactide and polycaprolatcon as potential materials for development of pleural implants. Further studies with scaling of laboratory samples and a detailed study of the dynamics of biodegradation of porous matrices in vivo in large animals are required. The need for further improvement in laboratory samples of bioresorbable pleural implants is associated with giving the porous matrices antibacterial, bioactive and X-ray contrast properties.
- Published
- 2021
4. Investigation of the nitride phase in a heat-resistant alloy of the Ni – Co – W – Ti system, hardened by internal nitration
- Author
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Yu. R. Kolobov, Fsue 'Viam', E. V. Filonova, S. V. Ovsepyan, M. V. Akhmedzyanov, S. S. Manokhin, and Ipcp Ras
- Subjects
Heat resistant ,Materials science ,Alloy ,technology, industry, and agriculture ,engineering.material ,Nitride ,equipment and supplies ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Phase (matter) ,Nitration ,engineering ,General Materials Science - Abstract
In a high-temperature alloy of the Ni – Co – Cr – W – Ti system grade VZh171, using X-ray spectral analysis, scanning and transmission electron microscopy, the composition of the particles of the hardening phase — nitrides after internal nitriding and subsequent heat treatment was studied. It was found that the particles differ on it chemical composition: the main constituent element, titanium or chromium, is proportionally replaced by other alloy components. The nitride compositions near the surface and in the center of the sample differ in the titanium to chromium ratio. After annealing, this difference is smaller, and the chromium content also decreases. It was found that the nitrides formed during nitriding are compounds in which the main forming element, titanium or chromium, is proportionally replaced by other alloy components. The nitride compositions near the surface and in the center of the sample differ in the titanium to chromium ratio. After annealing, this difference is smaller, and the chromium content also decreases.
- Published
- 2021
5. Investigation of Changes in the Structure of Submicrocrystalline Titanium of VT1-0 Brand under Heat Treatment and Laser Processing with Nanosecond Pulses
- Author
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M. V. Narykova, A. Yu. Tokmacheva-Kolobova, Yu. R. Kolobov, V. I. Betekhtin, A. G. Kadomtsev, Yu. Yu. Karlagina, and S. S. Manokhin
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010302 applied physics ,Materials science ,Annealing (metallurgy) ,chemistry.chemical_element ,02 engineering and technology ,Atmospheric temperature range ,Nanosecond ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,chemistry ,Transmission electron microscopy ,0103 physical sciences ,Irradiation ,Composite material ,Thin film ,0210 nano-technology ,Titanium - Abstract
The characteristic features of a change in the structure of samples of submicrocrystalline (SMC) technically pure titanium of VT1-0 brand after long-term annealing in a wide temperature range of 150–700°C with a duration of 0.5 to 1008 h, as well as after action by nanosecond laser pulses, are studied by transmission electron microscopy. It is found that the microstructure of the material under study remains stable during annealing for 1 h in the temperature range 150–400°C. Long-term (more than 1000 h) low-temperature annealing in the temperature range 150–190°C also does not lead to a significant change in the size of the structural elements. The action of nanosecond laser irradiation leads to additional grinding of the original SMC structure in the surface layers of the material to a depth of about 1 μm.
- Published
- 2021
6. Interlaboratory comparisons in the field of deformation measurements
- Author
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Yu. R. Shimolin, L. A. Tribushevskaia, and L. A. Ostroukhova
- Subjects
strain ,Materials science ,Strain (chemistry) ,Field (physics) ,lcsh:T ,tensoresistor ,Pure bending ,deformation ,Strain measurement ,Deformation (engineering) ,Composite material ,lcsh:Technology ,pure bending installation - Abstract
The article puts forward the concept of strain, the strain measurement units, means, methods and specifics of strain measurement. The round of interlaboratory comparisons in the field of measuring strain by determining the characteristics of tensoresistors with the help of pure bending installations. The results of the round, the analysis and the conclusions are presented.
- Published
- 2020
7. METHOD FOR MEASURING THE PRESSURE OF A SHOCK-ACOUSTIC WAVE OF AN ELECTRIC EXPLOSION OF A CONDUCTOR IN A DISCHARGE CHAMBER WITH A CONDENSED ENVIRONMENT
- Author
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Yu. R. Mukha and A. L. Surkaev
- Subjects
Materials science ,010401 analytical chemistry ,0202 electrical engineering, electronic engineering, information engineering ,020206 networking & telecommunications ,02 engineering and technology ,Acoustic wave ,Mechanics ,01 natural sciences ,0104 chemical sciences ,Conductor ,Shock (mechanics) - Abstract
An electric explosion of conductors, as well as an electric discharge as a whole, is a poorly studied unique phenomenon that is widely used both in basic scientific research and in various technological processes, which determines the relevance of further studies of ongoing processes. In this paper, we consider the methods and carry out calibration procedures to determine the value of the conversion coefficient for a piezoelectric pressure transducer with a reactive acoustic waveguide made of non-Newtonian fluid material. Designs of calibration plants are shown, the principle of which is based on the method of falling load and the interaction of parallel currents. The results of recording and measuring the pressure of a shock acoustic wave (SAW) generated by an electric explosion of a metal conductor of a ring-shaped geometry in a closed space of conical geometry with a condensed (aqueous) medium are presented. The discharge current and the voltage drop across the exploding flat ring foil (EEFRF) were recorded by the Rogowski belt and voltage divider, respectively. The pressure pulse of the acoustic shock wave was recorded by a piezoelectric pressure transducer. The electrical signals were recorded with a GDS-810 S digital two-beam storage oscilloscope. The amplitude value of pressure was estimated by plastic deformation of the plate sensor in the form of a round thin plate with clamped edges.
- Published
- 2020
8. Investigation of the Influence of Thermomechanical Treatment on the Structural-Phase State and Mechanical Properties of a VZh171 Alloy
- Author
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A. Yu. Tokmacheva-Kolobova, Yu. R. Kolobov, D. M. Levin, A. E. Ligachev, S. S. Manokhin, S. A. Bozhko, and S. V. Ovsepyan
- Subjects
010302 applied physics ,Materials science ,010308 nuclear & particles physics ,Annealing (metallurgy) ,Alloy ,General Physics and Astronomy ,Recrystallization (metallurgy) ,engineering.material ,Plasticity ,Microstructure ,01 natural sciences ,Grain size ,0103 physical sciences ,Ultimate tensile strength ,engineering ,Composite material ,Nitriding - Abstract
An analysis of the influence of thermomechanical treatment (TMT) (rolling to a strain degree of 50%, annealing at a temperatures of 600–1200°C, 1 h) on the microstructure and phase composition of a VZh171 alloy in the initial state and after its bulk nitriding is performed. It is shown that nitriding leads to an increase in the thermal stability of the alloy microstructure. While a primary recrystallization and formation of finegrained structure occurs in an non-nitrided alloy quite intensively at the temperature above 1000°C, the process of collective recrystallization does not gain any significant development in the nitrided alloy even at an annealing temperature of 1200°C, and the microstructure remains ultrafine-grained (grain size 5–10 μm). The mechanical properties of the nitrided and non-nitrided alloy are investigated. It is established that nitriding has no significant effect on the alloy strength at room temperature. In the tests at 800°C, the maximum strength and the minimum plasticity are demonstrated by the nitrided alloy after rolling and subsequent annealing at 600°C. The optimum ratio of the ultimate tensile strength (480 MPa) to plasticity (elongation to fracture 23%) is observed in the nitrided alloy after TMT and annealing at 800°C.
- Published
- 2020
9. Influence of Volume and Temperature Changes on Mechanical and Thermal Properties of PVC Filled with Nanodispersed Metals
- Author
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Humanities, Academician S. Demianchuk Str., Ua Rivne, Ukraine, V. V. Levchuk, B. B. Kolupaev, V. A. Sidletskii, O. S. Holub, B. S. Kolupaev, and Yu. R. Maksymtsev
- Subjects
Materials science ,Volume (thermodynamics) ,General Mathematics ,Thermal ,Metals and Alloys ,Composite material ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2020
10. About the Nature of Bead Lightning and Laboratory 'Plasmoids'
- Author
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D. A. Bulankin, Yu. R. Alanakyan, A. A. Tsvetkov, V. G. Pevgov, and L. V. Smirnov
- Subjects
Materials science ,Hydrogen ,Aqueous medium ,Computational Mechanics ,General Physics and Astronomy ,chemistry.chemical_element ,Plasmoid ,02 engineering and technology ,Plasma ,01 natural sciences ,Molecular physics ,Lightning ,010305 fluids & plasmas ,Bead (woodworking) ,Atmosphere ,020303 mechanical engineering & transports ,0203 mechanical engineering ,chemistry ,Physics::Plasma Physics ,Mechanics of Materials ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Electric discharge ,Physics::Atomic Physics ,Physics::Atmospheric and Oceanic Physics - Abstract
The results of experimental investigations of an electric discharge in an aqueous medium are presented. In the experiment, the formation of luminous balls, which sometimes exploded, is observed in the atmosphere. Spectroscopic investigations show the presence of an increased content of atomic hydrogen in the plasma, which confirms the assumption that the balls formed could be diffusely burning hydrogen clumps. The results obtained suggest that bead lightning is similar to diffusely burning hydrogen formations.
- Published
- 2020
11. A well-isolated vibrational state of CO2verified by near-infrared saturated spectroscopy with kHz accuracy
- Author
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Hao Wu, Jin Wang, An-Wen Liu, Yan Tan, Shui-Ming Hu, Chang-Le Hu, and Yu R. Sun
- Subjects
Materials science ,010504 meteorology & atmospheric sciences ,Spectrometer ,Sensing applications ,Near-infrared spectroscopy ,General Physics and Astronomy ,State (functional analysis) ,Saturated spectroscopy ,01 natural sciences ,Quantitative determination ,Co2 concentration ,0103 physical sciences ,Physical and Theoretical Chemistry ,Atomic physics ,010306 general physics ,0105 earth and related environmental sciences ,Line (formation) - Abstract
Quantitative determination of atmospheric CO2 concentration by remote sensing relies on accurate line parameters. Lamb dips of the lines up to J′′ = 72 in the 30013–00001 band at 1605 nm were measured using a comb-locked cavity ring-down spectrometer, and the positions were determined with an accuracy of a few kHz. A simple effective Hamiltonian model can fit the rotational energies in the 30013 state ideally within the experimental accuracy, indicating that the vibrational state is well-isolated and can be regarded as free from perturbations. From a comparison between other bands using a similar analysis, we conclude that the transitions in the 30013–00001 band could be more suitable as reference lines for sensing applications with the potentially improved line parameter accuracy.
- Published
- 2020
12. Anode dissolution of double Pb-Sb and Pb-Bi alloys and electrochemical separation of ternary Pb-Sb-Bi alloys in the KCl-PbCl2 melt
- Author
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P. A. Arkhipov, Yu. R. Khalimullina, A. S. Kholkina, and Yu. P. Zaykov
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Materials science ,Electrolytic cell ,General Chemical Engineering ,General Engineering ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Cathode ,0104 chemical sciences ,Anode ,Bismuth ,law.invention ,chemistry ,Antimony ,law ,General Materials Science ,0210 nano-technology ,Polarization (electrochemistry) ,Dissolution - Abstract
The paper is aimed at the study of the influence of bismuth, antimony, and lead concentrations on the Pb-Bi, Sb-Pb alloys anode dissolution in the equimolar KCl-PbCl2 melt. The process of lead dissolution, which occurs at the potentials close to equilibrium ones, was found to be a basic process up to the definite values of current densities. According to changes in the theoretical and experimental polarization curves, the element concentrations at the liquid anodes surface were evaluated depending on the current load. The electrolytic cell with a bipolar metallic electrode, the electrolytic cell with two anodes and one cathode, and the electrolytic cell with a porous diaphragm were studied. The tests demonstrated that lead is effectively separated from the metal impurities in all constructions under study.
- Published
- 2019
13. Study of irradiated graphite-bakelite paste
- Author
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M.V. Antonenko, E.V. Bespala, V.N. Kotov, I. Yu. Novoselov, and Yu. R. Bespala
- Subjects
Nuclear and High Energy Physics ,Materials science ,Materials Science (miscellaneous) ,01 natural sciences ,010305 fluids & plasmas ,chemistry.chemical_compound ,Graphite-bakelite paste ,Stack (abstract data type) ,0103 physical sciences ,Bakelite ,Graphite ,Irradiation ,Wigner effect ,Decommissioning ,010302 applied physics ,Wigner energy ,Radionuclide ,Metallurgy ,TK9001-9401 ,Actinide ,Graphite stack ,Nuclear Energy and Engineering ,chemistry ,Irradiated graphite ,Leaching ,Nuclear engineering. Atomic power ,Leaching (metallurgy) - Abstract
The article is devoted to the study of irradiated graphite-bakelite paste formed during the restoration of graphite stack and the operation of uranium-graphite reactors. It was shown that irradiation of graphite-bakelite paste in the reactor leads to the formation of long-lived radionuclides and the accumulation of Wigner energy. The studies of graphite-bakelite paste extracted from the graphite stack of one of the UGR with a closed primary loop showed that the samples of graphite-bakelite paste are contaminated unevenly with 137Cs, 154Eu, 60Co, and 241Am radionuclides (fission and activation products and actinides). From the results of experiments on leaching of radionuclides from graphite-bakelite paste, it can be seen that radionuclides 241Am and 137Cs are more subjected to leaching. The estimation of the stored energy in the selected samples shows that the heat release begins at a temperature of 600–650 ◦C. The largest amount of stored energy is released at a temperature of 750 ◦C. Moreover, the magnitude of this quantity does not exceed 1–6 J/g. It was also shown that the development of the concept and program for decommissioning of UGR, the stack of which was restored using graphite-bakelite paste, requires additional studies to determine the potential danger of irradiated graphite-bakelite paste.
- Published
- 2021
14. Testing of electrocorundum powders of the company «Technoceramics» in the manufacture of ceramic molds
- Author
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I. V. Dyakonova, M. A. Gorbanenko, S. I. Polyansky, T. F. Baranova, N. I. Shunkina, and Yu. R. Nurtdinov
- Subjects
Nickel ,Materials science ,chemistry ,Internal cavity ,Casting (metalworking) ,visual_art ,Metallurgy ,General Engineering ,visual_art.visual_art_medium ,chemistry.chemical_element ,Ceramic - Abstract
The technology of manufacturing ceramic molds from electrocorundum powders of the company «Technoceramics» for the casting of parts from heatresistant nickel alloys was investigated and developed. The powders were used instead of the commercially used electrocorundum powders of JSC Rusal. Molds for metal casting of various sizes and configurations of the internal cavity for casting cooled and uncooled blades of heat-resistant alloys were manufactured and tested. Technical properties of casting molds are preserved. The characteristics of castings of equiaxial and directional structure are provided in accordance with the technical requirements of the drawing and technical conditions. Ill. 5. Ref. 2. Tab. 6.
- Published
- 2019
15. Effect of High-Power Ion Beams on the Surface Topography and Structure of the Subsurface Layer of Submicrocrystalline Titanium Alloys
- Author
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G. E. Remnev, Yu. R. Kolobov, A. E. Ligachev, G. V. Potemkin, and M. V. Zhidkov
- Subjects
010302 applied physics ,Materials science ,Alloy ,Metals and Alloys ,Pulse duration ,Titanium alloy ,02 engineering and technology ,engineering.material ,01 natural sciences ,Surface energy ,Grain size ,020501 mining & metallurgy ,Surfaces, Coatings and Films ,Micrometre ,Grain growth ,0205 materials engineering ,Mechanics of Materials ,0103 physical sciences ,engineering ,Irradiation ,Composite material - Abstract
The influence of high-power beams of carbon ions (the ion energy is 250 keV; the pulse duration is ~100 ns; the current density in the pulse is 150–200 A/cm2; the surface energy density of a single pulse is j ~ 3 J/cm2 under the irradiation of the samples of the VT1-0 titanium alloy and j ~ 1 J/cm2 for the treatment of the samples of the VT6 titanium alloy; and the number of pulses is 1, 5, 10, and 50) on the surface topography and structure-phase state of the subsurface layer of submicrocrystalline titanium alloys VT1-0 and VT6 is studied. The sample surface before irradiation is preliminarily mechanically grinded and polished. It is shown that surface defects are formed on the alloy surface after irradiation. These are craters of various shapes and geometry with diameter from fractions of micrometer to 80–100 μm. Herewith, the grain structure in the subsurface layer becomes more uniform in size and degree of grain equiaxity. A rather homogeneous structure is characteristic of the state of the VT1-0 titanium alloy; the average grain size is ~0.31 μm, while that one the VT6 alloy is ~0.9 μm. The grain growth in the transverse direction to 0.54 μm is observed after one irradiation pulse in the subsurface layer of the VT1-0 alloy (at j ~ 3 J/cm2), while the grain size for the VT6 alloy (j ~ 1 J/cm2) decreases to ~0.54 μm. The average grain size in the subsurface layer after 50 pulses reaches ~2.2 μm for the VT1-0 alloy and ~1.6 μm for the VT6 alloy. It should be noted that a rather homogeneous grain structure with equiaxial grains is formed for both alloys already after the effect of one pulse of the high-power ion beam.
- Published
- 2019
16. Ni-Co-Cr/Al2O3/Al Catalysts with a Nanostructured Active Component: Microwave-Assisted Synthesis and Activity in the Reaction of Toluene Steam Dealkylation
- Author
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S. M. Zul’fugarova, A. M. Ilolov, Yu. N. Litvishkov, R. M. Talyshinskii, V. F. Tret’yakov, P. A. Muradova, Yu. R. Nagdalieva, and N. V. Shakunova
- Subjects
Materials science ,010405 organic chemistry ,General Chemical Engineering ,Energy Engineering and Power Technology ,General Chemistry ,Alkylation ,Active surface ,010402 general chemistry ,01 natural sciences ,Toluene ,0104 chemical sciences ,Catalysis ,Reaction rate ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Chemical engineering ,Geochemistry and Petrology ,Selectivity ,Benzene ,Microwave - Abstract
It is shown that the reaction of toluene steam dealkylation can be intensified in the presence of microwave radiation-absorbing Ni-Co-Cr/Al2O3/Al catalysts with the nanostructured active component under application of a microwave electromagnetic field to the reaction medium. It is found that the favorable effect of microwave radiation on the rate of reaction and selectivity for the target product benzene is most probably related to the formation of a more developed active surface owing to the formation of Ni and Co chromites as uniformly distributed nanosized clusters with linear sizes of 20–80 nm.
- Published
- 2019
17. Dissipative Structures of the Polyvinylchloride Filled with the Nanodisperse Metals
- Author
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B. S. Kolupaev, B. B. Kolupaev, V. O. Sidletskyy, Yu. R. Maksimtsev, T. G. Lyashuk, and V. V. Levchuk
- Subjects
Materials science ,General Mathematics ,Metals and Alloys ,Dissipative system ,Composite material ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2019
18. Optical-Optical Double-Resonance Absorption Spectroscopy of Molecules with Kilohertz Accuracy
- Author
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An-Wen Liu, Tian-Peng Hua, Shui-Ming Hu, Jin Wang, C.-F. Cheng, Chang-Le Hu, V.I. Perevalov, Yu R. Sun, and Yan Tan
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Materials science ,010504 meteorology & atmospheric sciences ,Absorption spectroscopy ,business.industry ,Physics::Optics ,Rotation ,Laser ,01 natural sciences ,law.invention ,Frequency comb ,law ,Excited state ,0103 physical sciences ,Optoelectronics ,Molecule ,General Materials Science ,Physical and Theoretical Chemistry ,010306 general physics ,business ,Spectroscopy ,0105 earth and related environmental sciences ,Diode - Abstract
Selective pumping and probing of highly excited states of molecules are essential in various studies but are also challenging because of high density of states, weak transition moments, and lack of precise spectroscopy data. We develop a comb-locked cavity-assisted double-resonance spectroscopy (COCA-DR) method for precision measurements using low-power continuous-wave lasers. A high-finesse cavity locked with an optical frequency comb is used to enhance both the pumping power and the probing sensitivity. As a demonstration, Doppler-free stepwise two-photon absorption spectra of CO2 were recorded by using two milliwatt diode lasers (1.60 and 1.67 μm), and the rotation energies in a highly excited state (CO-stretching quanta = 8) were determined with an unprecedented accuracy of a few kilohertz.
- Published
- 2020
19. The N-body interatomic potential for molecular dynamics simulations of diffusion in tungsten
- Author
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V.N. Maksimenko, A.I. Kartamyshev, A.G. Lipnitskii, Yu. R. Kolobov, and D.O. Poletaev
- Subjects
Materials science ,General Computer Science ,General Physics and Astronomy ,Thermodynamics ,chemistry.chemical_element ,Interatomic potential ,General Chemistry ,Tungsten ,Thermal expansion ,Computational Mathematics ,Molecular dynamics ,chemistry ,Diffusion process ,Mechanics of Materials ,Melting point ,General Materials Science ,Diffusion (business) ,Homologous temperature - Abstract
Tungsten, as the most refractory metal, is applied in fusion reactor in parts subjected to high temperatures and strong neutron irradiation. These factors lead to intense diffusion processes causing degradation of the material. Experimental investigations under such conditions are usually highly complicated and cannot provide a comprehensive understanding of the occurring phenomena. Therefore, their combination with theoretical approaches is required. One of the most robust approaches to simulate diffusion processes is molecular dynamics simulations based on classical interatomic potentials. It allows modeling relatively large samples consisting of several grains, grain boundaries, dislocations, and other types of defects for a reasonable computational time. The reliable simulations of the diffusion process require interatomic potentials satisfying the following criteria: prediction of melting point and thermal expansion as close as possible to the experimental values because the diffusion coefficient strongly depends on the homologous temperature and size factor. In the present paper, we present the new interatomic potential for tungsten, developed within the N-body approach, which reproduces the experimental value of melting temperature (3695 K) and thermal expansion at temperatures up to a melting point. The calculated diffusion coefficient demonstrates adequate agreement with experimental results. The constructed potential is applicable for simulation of processes involving diffusion, one of which is the irradiation damage.
- Published
- 2022
20. Comparative Study of the Structural-Phase State and Mechanical Properties of Ni–Cr(X) and Fe–Cr(X) Heat-Resistant Alloys Fabricated by Additive Technologies
- Author
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Yu. R. Kolobov, A. Yu. Tokmacheva-Kolobova, A. N. Prokhorov, D. I. Serebryakov, V. V. Afanasiev, and S. S. Manokhin
- Subjects
Materials science ,Annealing (metallurgy) ,Alloy ,technology, industry, and agriculture ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,equipment and supplies ,021001 nanoscience & nanotechnology ,Surfaces, Coatings and Films ,Nickel ,Chromium ,020303 mechanical engineering & transports ,0203 mechanical engineering ,chemistry ,Mechanics of Materials ,Ultimate tensile strength ,engineering ,Lamellar structure ,Thermal stability ,Selective laser melting ,Composite material ,0210 nano-technology - Abstract
Comparative studies of peculiarities of the formation, thermal stability of the structure, and mechanical properties of heat-resistant alloys based on iron and nickel and fabricated using additive technologies (ATs) by laser metal deposition and selective laser melting are performed. It is established that a cellular structure is formed in alloys fabricated by the laser metal deposition and small pores up to 200 nm in size are present. The structure of alloys fabricated by selective laser melting contains elements with a globular and lamellar morphology and incompletely melted regions, as well as large pores on the order of 5 μm in size. The possibility of manifestation of the nanophase hardening effect due to the presence of nanodimensional particles of chromium silicides is shown. A comparative analysis of mechanical properties of materials under study is performed. It is shown that iron-based alloys possess higher strength and lower ductility when compared with nickel alloys. All studied samples fabricated by selective laser melting have higher strength characteristics when compared with alloys fabricated by laser metal deposition. Short-term annealing at 900–1000°C for 1 h noticeably decreases both strength and plasticity in tensile and compression tests at room and elevated temperatures. Alloys based on iron and nickel fabricated by laser metal deposition and subjected to compression tests at t = 900°C have similar strength characteristics. In contrast with iron-based alloys, additional annealing of the nickel-based AT alloy almost does not decrease its strength characteristics.
- Published
- 2018
21. Thermal Fluctuations of Electromagnetic Field in the PVC Filled with Micro- and Nanodisperse Graphite
- Author
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B. B. Kolupaev, V. V. Levchuk, B. S. Kolupaev, V. O. Sidletsky, and Yu. R. Maksymtsev
- Subjects
Electromagnetic field ,Materials science ,020209 energy ,General Mathematics ,Metals and Alloys ,Thermal fluctuations ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,0202 electrical engineering, electronic engineering, information engineering ,Graphite ,Composite material ,0210 nano-technology - Published
- 2018
22. Comparative study of structural phase condition and mechanical properties of Ni–Cr(X) и Fe–Cr(Х) heat-resistant alloys obtained using additive technologies
- Author
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A. Yu. Tokmacheva-Kolobova, S. S. Manokhin, A. N. Prokhorov, D. I. Serebryakov, V. V. Afanasiev, and Yu. R. Kolobov
- Subjects
Materials science ,Annealing (metallurgy) ,Materials Science (miscellaneous) ,Metals and Alloys ,chemistry.chemical_element ,Surfaces, Coatings and Films ,Nickel ,Chromium ,chemistry ,Direct metal laser sintering ,Ultimate tensile strength ,Ceramics and Composites ,Hardening (metallurgy) ,Lamellar structure ,Composite material ,Selective laser melting - Abstract
The comparative study covers the features of formation, thermal stability of structure and mechanical properties of heatresistant Ni and Fe based alloys obtained using additive technologies (AT) by direct metal laser sintering, selective laser melting. It is found that alloys obtained by direct metal laser sintering have a cellular structure formed with small pores up to 200 nm in size, in contrast to alloys obtained by selective laser melting having elements with a globular and lamellar morphology and not completely melted areas as well as large pores about 5 μm in size. The study reveals a possible effect of nanophase hardening due to the presence of nanosized particles of chromium silicides in the material. A comparative analysis of the mechanical properties of studied materials is carried out. It is shown that the iron-based alloys have higher strength and lower ductility compared to nickel alloys. All studied samples obtained by selective laser melting demonstrate higher strength characteristics in comparison with alloys obtained by laser metal deposition. As a result of short-term annealing at a temperature of 900–1000 °C for 1 h leads to a significant reduction in the plasticity and strength of iron-based AT alloys during tensile and compression tests at room and elevated temperatures. During compression tests at t = 900 °C, iron-and nickel-based alloys obtained by laser metal deposition have similar strength characteristics. Unlike iron-based alloys, additional annealing of nickel-based AT alloys has virtually no impact on its strength properties.
- Published
- 2018
23. Regularities and Mechanisms of Formation of Submicro-, Nano-, and Ultrafine-Grained Structures and Mechanical Properties of Metals and Alloys Under Different Treatments
- Author
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Yu. R. Kolobov
- Subjects
010302 applied physics ,Nanostructure ,Materials science ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Plasticity ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Grain size ,chemistry ,0103 physical sciences ,Nano ,Irradiation ,Composite material ,Deformation (engineering) ,0210 nano-technology ,Titanium - Abstract
An overview of our original studies and the results reported in the literature on the investigation of variations in structure, phase composition, mechanical and other properties of metallic materials under external impacts is made, including their high-pressure processing by large (severe) plastic and megaplastic deformation, explosion loading, and irradiation with ultra-short laser pulses.
- Published
- 2018
24. Structural Changes in Refractory Calcium Aluminate Cement Concrete
- Author
-
T. V. Kuznetsova, Yu. R. Krivoborodov, and S. V. Samchenko
- Subjects
Cement ,Materials science ,Aluminate ,Metallurgy ,0211 other engineering and technologies ,chemistry.chemical_element ,02 engineering and technology ,Calcium ,021001 nanoscience & nanotechnology ,chemistry.chemical_compound ,chemistry ,Phase (matter) ,021105 building & construction ,Materials Chemistry ,Ceramics and Composites ,0210 nano-technology ,Refractory (planetary science) - Abstract
The influence of both organic and inorganic additives to calcium aluminate cement on the processes of hydration and structure formation of concrete both at normal and elevated temperatures is investigated here. The results of investigating phase transformations in hardened calcium aluminate samples during heating from 20 to 900°C are given. The structure change mechanism and the reasons for the reduction of the strength of concrete under the influence of high temperatures are described.
- Published
- 2018
25. Effect of a Nanodisperse Graphite on the Viscoelastic Properties of Polyvinyl Chloride
- Author
-
Yu. R. Maksimtsev, V. V. Levchuk, V. A. Sidletskii, B. B. Kolupaev, B. S. Kolupaev, and B. D. Nechyporuk
- Subjects
Electrolysis ,Materials science ,Polymers and Plastics ,General Mathematics ,Composite number ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Viscoelasticity ,law.invention ,Biomaterials ,Shear modulus ,Polyvinyl chloride ,chemistry.chemical_compound ,020303 mechanical engineering & transports ,0203 mechanical engineering ,chemistry ,Volume (thermodynamics) ,Mechanics of Materials ,law ,Ceramics and Composites ,Compressibility ,Graphite ,Composite material ,0210 nano-technology - Abstract
In the absence of segregation of nanodisperse graphite particles, obtained by electrolysis as a new filler of polyvinyl chloride (PVC), the viscoelastic phenomena dependent on the structural changes of a composite are investigated. The shear modulus and the volume compressibility caused by deviations of elements of the structure from the quasi-equilibrium state under the action of ultrasonic vibrations (ω = 0.4·106 0.4 · 10 s–1) are calculated at filler concentrations 0 ≤ φ ≤ 10.0 vol.% and temperatures 298 K ≤ T ≤ (Tg + 10) K. It is shown that the volume density of internal energy depends on the expectation time for the transition of structural elements through the energy barrier, the dynamic viscosity of the material, and temperature. The results of calculations serve as the basis for producing PVC systems with controllable of properties.
- Published
- 2018
26. Transformations in the Grain Boundary Ensemble of M1 Copper Subjected to Equal-Channel Angular Pressing during Recrystallization Annealing
- Author
-
Yu. R. Kolobov, E. V. Konovalova, A. I. Korshunov, and O. B. Perevalova
- Subjects
010302 applied physics ,Diffraction ,Materials science ,Condensed matter physics ,Annealing (metallurgy) ,Scanning electron microscope ,General Physics and Astronomy ,Recrystallization (metallurgy) ,02 engineering and technology ,Electron ,021001 nanoscience & nanotechnology ,01 natural sciences ,Grain size ,Transmission electron microscopy ,0103 physical sciences ,Grain boundary ,0210 nano-technology - Abstract
The grain structure of M1 copper subjected to equal-channel angular pressing (ECAP) and subsequent annealing at 593K for 1 h is studied by means of transmission electron microscopy and scanning electron microscopy with the diffraction of backscattered electrons. An increase in grain size and the formation of special boundaries (Σ3 twins both coherent and incoherent) are observed, along with the migration of high-energy Σ3 twins and common grain boundaries, the splitting of Σ9 special boundaries into Σ3 twins, and the splitting of common grain boundaries into Σ9 and Σ3 special boundaries. The local transformation of common grain boundaries into special boundaries also occurs. Particles of the Cu2O phase are present on the migrating Σ3 twins and common grain boundaries.
- Published
- 2018
27. High-Sensitivity Photodetector Based on Atomically Thin MoS2
- Author
-
A. P. Shestakova, Elena Mishina, Yu. R. Efimenkov, S. D. Lavrov, and A. S. Sigov
- Subjects
Materials science ,Fabrication ,business.industry ,Process (computing) ,Photodetector ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Characterization (materials science) ,Quality (physics) ,Photosensitivity ,Optoelectronics ,0210 nano-technology ,business ,Sensitivity (electronics) ,Voltage - Abstract
A design for a high-sensitivity photodetector with a single layer of MoS2 transition-metal dichalcogenide used as the basic functional element is proposed and the process of its fabrication is presented step by step. Quality evaluation and the selection of functional MoS2 flakes is based on the results of combined optical characterization. The main operating characteristics of the fabricated device are investigated and a photosensitivity of 1.4 mA/W is demonstrated. A difference of this device in comparison with existing analogues is its high photosensitivity at low operating voltages (in the range of ±3 V).
- Published
- 2018
28. Frequency metrology of the acetylene lines near 789 nm from lamb-dip measurements
- Author
-
Jin Wang, Lei-Gang Tao, An-Wen Liu, Shui-Ming Hu, Tian-Peng Hua, and Yu R. Sun
- Subjects
Work (thermodynamics) ,Radiation ,Materials science ,010504 meteorology & atmospheric sciences ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Cavity ring-down spectroscopy ,Metrology ,010309 optics ,chemistry.chemical_compound ,Acetylene ,chemistry ,0103 physical sciences ,Optical frequency comb ,Atomic physics ,Saturation (chemistry) ,Spectroscopy ,Order of magnitude ,0105 earth and related environmental sciences - Abstract
Lamb-dips of the ro-vibrational lines of 12C2H2 near 789 nm were recorded using cavity ring-down saturation spectroscopy. Calibrated by an optical frequency comb, frequencies of 45 acetylene lines were determined with an accuracy of 1.1 × 10 − 7 cm − 1 ( δ ν / ν = 8 × 10 − 12 ), which is over two orders of magnitude more accurate than previous Doppler-limited studies. An averaged shift of about 0.01 cm − 1 were found by comparing the upper energies obtained in this work to those recently presented by Chubb et al. from a MARVEL analysis.
- Published
- 2018
29. Superlattices in a metal-nanodisperse polyvinylchloride
- Author
-
V.A. Sidletskyi, Yu. R. Maksimtsev, B. S. Kolupaev, V. V. Levchuk, and B. B. Kolupaev
- Subjects
010302 applied physics ,Materials science ,0103 physical sciences ,02 engineering and technology ,021001 nanoscience & nanotechnology ,0210 nano-technology ,01 natural sciences - Published
- 2018
30. Development of Enamel Coatings for Advanced CCGT Installations
- Author
-
Yu. R. Gil’metdinova, K. V. Kazak, A. F. Ryzhkov, A. K. Kazak, and V. A. Mikula
- Subjects
Materials science ,Enamel paint ,Metallurgy ,Composite number ,Oxide ,Heat resistance ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Refractory (planetary science) - Abstract
High temperature enamel coatings with quite high firing temperature, which impart the required protective properties and heat resistance, were obtained. The results of scientific and experimental studies of the parameters and properties of the obtained coatings based on composite make-up modified by additives of refractory fillers introduced by via nanosize oxide powders are presented.
- Published
- 2018
31. Ignition of a Ti–Al–C System by an Electron Beam
- Author
-
Yu. M. Maksimov, A. E. Ligachev, O. K. Lepakova, A. D. Teresov, G. V. Potemkin, M. V. Zhidkov, N. N. Koval, Yu. R. Kolobov, and N. N. Golobokov
- Subjects
Elemental composition ,Materials science ,010304 chemical physics ,General Chemical Engineering ,Self-propagating high-temperature synthesis ,General Physics and Astronomy ,Energy Engineering and Power Technology ,General Chemistry ,01 natural sciences ,010406 physical chemistry ,0104 chemical sciences ,law.invention ,Ignition system ,Microsecond ,Fuel Technology ,law ,0103 physical sciences ,Cathode ray ,Physics::Accelerator Physics ,Particle ,Atomic physics ,Powder mixture - Abstract
This paper describes the optimal modes of initiation of self-propagating hightemperature synthesis with the help of an electron beam on the example of a Ti–Al–C powder mixture. A pulsed electron beam with a particle energy of tens of kiloelectronvolts and a duration of hundreds of microseconds is used. Morphology, structure, and elemental composition of formed products in the form of Ti3AlC2 and TiC are studied.
- Published
- 2018
32. Effect of Processing by Femtosecond Pulsed Laser on Mechanical Properties of Submicrocrystalline Titanium
- Author
-
I. N. Kuz’menko, S. S. Manokhin, Sergey V. Makarov, Andrey A. Ionin, A. N. Skomorokhov, V. I. Betekhtin, Yu. R. Kolobov, E. A. Korneeva, Sergey I. Kudryashov, A. Yu. Kolobova, and A. G. Kadomtsev
- Subjects
010302 applied physics ,Materials science ,Physics and Astronomy (miscellaneous) ,Femtosecond pulsed laser ,Titanium alloy ,chemistry.chemical_element ,Fatigue testing ,02 engineering and technology ,Deformation (meteorology) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Cantilever bending ,chemistry ,0103 physical sciences ,Femtosecond ,Composite material ,0210 nano-technology ,Laser processing ,Titanium - Abstract
Effect of femtosecond laser processing on mechanical properties of plates made of submicrocrystalline VT1-0 titanium alloy is studied using active deformation and fatigue testing involving cantilever bending.
- Published
- 2018
33. Morphology of titanium surface after irradiation by pulsed X-ray radiation
- Author
-
S. A. Sorokin, G. V. Potemkin, A. E. Ligachev, Yu. R. Kolobov, and M. V. Zhidkov
- Subjects
Materials science ,Morphology (linguistics) ,Analytical chemistry ,X-ray ,General Materials Science ,Titanium surface ,Irradiation ,Radiation - Published
- 2018
34. Properties of Optical Ceramics CO1 and CO2 upon Modification of Their Surface by Carbon Nanotubes
- Author
-
Yu. R. Zagidullina, S. V. Likhomanova, and Natalia V. Kamanina
- Subjects
010302 applied physics ,Surface (mathematics) ,Materials science ,Physics and Astronomy (miscellaneous) ,Surface modified ,02 engineering and technology ,Carbon nanotube ,021001 nanoscience & nanotechnology ,01 natural sciences ,Spectral line ,law.invention ,law ,visual_art ,0103 physical sciences ,visual_art.visual_art_medium ,Deposition (phase transition) ,Ceramic ,Wetting ,Composite material ,0210 nano-technology ,Refractive index - Abstract
The results of a study of the modification of the properties of optical inorganic materials (optical ceramics CO1 (MgF2) and CO2 (ZnS)) are presented. It is found that the main characteristics of the studied materials with a surface modified by carbon nanotubes significantly changes when the laser-oriented deposition method is applied. Main features of the carbon nanotubes caused by its developed surface, the strength of C–C bonds, and low value of refraction index are taken into consideration. Analytical, quantum-chemical and experimental results of studies of changes in the spectral and mechanical parameters, as well as the wetting angle of the selected model inorganic matrices, are given.
- Published
- 2019
35. Condition of Surface of Titanium after Pulsed X-ray Exposure
- Author
-
S. A. Sorokin, A. E. Ligachev, G. V. Potemkin, M. V. Zhidkov, and Yu. R. Kolobov
- Subjects
010302 applied physics ,Surface (mathematics) ,Materials science ,Molten metal ,General Engineering ,Titanium alloy ,Radiant energy ,Flux ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,X ray exposure ,01 natural sciences ,Pulse (physics) ,chemistry ,0103 physical sciences ,General Materials Science ,Composite material ,0210 nano-technology ,Titanium - Abstract
The effect of the pulsed soft X-ray flux on the topography of surface the VТ 1-0 titanium alloy has been studied. The radiation energy density on the surface of the sample is ~10 J/cm2 for one pulse. It is found that a corrugated topography is formed on the surface of titanium as a result of melting followed by freezing: a cellular- or mesh-type topography is formed after one X-ray pulse, the mesh-type topography becomes more sharply defined after two pulses, and the surface of titanium is melted and the mesh structure is almost invisible after three pulses. Crater-like defects are not found, but small cracks are formed on the surface of titanium after melting caused by pulsed X-ray exposure followed by fast cooling of the molten metal.
- Published
- 2019
36. The Formation of Oxide Layers on a Titanium Surface by Irradiation with Femtosecond Laser Pulses
- Author
-
Yu. R. Kolobov, Andrey A. Ionin, E. V. Golosov, T. N. Vershinina, Sergey I. Kudryashov, M. V. Zhidkov, and V. I. Betekhtin
- Subjects
010302 applied physics ,Materials science ,Physics and Astronomy (miscellaneous) ,business.industry ,Scanning electron microscope ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,Microporous material ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,Nanocrystalline material ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Transmission electron microscopy ,0103 physical sciences ,Femtosecond ,Optoelectronics ,0210 nano-technology ,business ,Titanium - Abstract
By subjecting technical grade titanium to irradiation with femtosecond laser pulses with high energy density, we create a microporous nanocrystalline oxide layer with a thickness of ∼50 μm on its surface. The structure and phase composition of the modified surface layers are studied using X-ray diffraction and high-resolution scanning and transmission electron microscopies.
- Published
- 2018
37. Effect of pulsed soft X-ray radiation on the surface topography of some metals
- Author
-
G. V. Potemkin, M. V. Zhidkov, Yu. R. Kolobov, S. A. Sorokin, and A. E. Ligachev
- Subjects
Surface (mathematics) ,History ,Soft x ray ,Materials science ,Optics ,business.industry ,Radiation ,business ,Computer Science Applications ,Education - Abstract
Effect of the pulsed soft X-ray fluxes (PSXF) on the surface topography of metals (Mg and Cu) has been investigated. Soft pulse X-ray irradiation (energy quanta of 0.1-1.0 keV) were carried out on a high-current MIG generator. The sample of magnesium was located at a distance of 10 cm from the X-ray source. Since the distance to the sample significantly exceeded the size of the X-ray beam, it can be assumed that the density of the X-ray radiation flow to the magnesium sample was uniform. The duration of the radiation pulse was 100 ns, and the radiation energy density in the pulse varied from 13 to 19 J/cm2. As a result of melting under the action of PSXF of the near-surface layer of metals and subsequent solidification, a wavy relief is formed on their surface. Defects in the form of craters, which usually occur after the impact of a powerful pulsed ion flow on metals, were not detected.
- Published
- 2021
38. Lead production using molten chloride electrolytes
- Author
-
A. S. Kholkina, Yu. R. Khalimullina, P. A. Arkhipov, and N. G. Molchanova
- Subjects
Lead (geology) ,Materials science ,Chloride electrolytes ,Inorganic chemistry ,Materials Chemistry ,Metals and Alloys ,Ceramics and Composites ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films - Published
- 2017
39. Regularities of Formation and Degradation of the Microstructure and Properties of New Ultrafine-Grained Low-Modulus Ti–Nb–Mo–Zr Alloys
- Author
-
O. A. Golosova, Yu. R. Kolobov, and S. S. Manokhin
- Subjects
010302 applied physics ,Materials science ,Annealing (metallurgy) ,Alloy ,Metals and Alloys ,chemistry.chemical_element ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Grain size ,Surfaces, Coatings and Films ,chemistry ,Mechanics of Materials ,0103 physical sciences ,engineering ,Dynamic recrystallization ,Grain boundary ,Composite material ,0210 nano-technology ,Electron backscatter diffraction ,Titanium - Abstract
—Regularities of the formation of ultrafine-grained (UFG) and submicrocrystalline (SMC) structures in new nickel-free low-modulus Ti–Nb–Mo–Zr titanium β alloys under the action of plastic deformation have been studied. Temperature–time ranges of the development of dynamic recrystallization processes under the simultaneous action of temperature and plastic deformation are determined. A type-II recrystallization diagram of the Ti–28Nb–8Mo–12Zr alloy is constructed and analyzed. It is shown using scanning electron microscopy and the electron backscatter diffraction method that the UFG structure with an average grain size of no more than 7 μm and high fraction of high-angle grain boundaries is formed in the investigated alloys as a result of longitudinal rolling, followed by annealing for quenching. It is found that the formation of the UFG structure leads to a significant increase in the strength and plastic characteristics of these alloys. The regularities of the formation of UFG and SMC structures in titanium β alloys Ti–28Nb–8Mo–12Zr and industrial VT30 under the action of plastic deformation by the helical rolling method are studied. It is shown that the helical rolling of the VT30 alloy leads to the formation of the homogeneous UFG state as opposed to the Ti–28Nb–8Mo–12Zr alloy, where this method causes structure softening with micropores and microcracks formed in the central region. It is possible to form a nanostructured state with an average grain size of about 100 nm in Ti–Nb–Mo–Zr titanium β alloys using the high-pressure torsion method.
- Published
- 2017
40. Elastic and microplastic properties of titanium in different structural states
- Author
-
B. K. Kardashev, M. V. Narykova, Yu. R. Kolobov, A. G. Kadomtsev, and V. I. Betekhtin
- Subjects
010302 applied physics ,Materials science ,Physics and Astronomy (miscellaneous) ,Modulus ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Grain size ,Metal ,chemistry ,visual_art ,0103 physical sciences ,visual_art.visual_art_medium ,Deformation (engineering) ,Severe plastic deformation ,Composite material ,0210 nano-technology ,Titanium - Abstract
The behavior of elastic (Young’s modulus) and microplastic properties of titanium depending on the initial structure and subsequent severe plastic deformation that transforms the material (concerning the grain size) into the submicrocrystalline structural state has been studied. It has been shown that, to a great extent, different initial structures of the metal predetermine its elastic properties after deformation.
- Published
- 2017
41. Defect structure and thermomechanical stability of nano- and microcrystalline titanium obtained by different methods of intense plastic deformation
- Author
-
M. V. Narykova, Yu. R. Kolobov, A. G. Kadomtsev, Vaclav Sklenicka, and V. I. Betekhtin
- Subjects
010302 applied physics ,Materials science ,Solid-state physics ,Annealing (metallurgy) ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Microcrystalline ,chemistry ,Mechanical stability ,0103 physical sciences ,Nano ,Grain boundary ,Composite material ,0210 nano-technology ,Thermostability ,Titanium - Abstract
Mechanical stability under prolonged loading and thermostability under annealing have been studied for nano- and microcrystalline titanium obtained by different methods of intense plastic deformation. The effect of nanoporosity and the fraction of high angle boundaries formed due to intense plastic deformation has been revealed and analyzed. It has been established that, depending on the loading or the annealing temperature, thermomechanical stability of titanium can be affected, apart from the above structural characteristics, by either twin grain boundaries or titanium-carbide disperse particles.
- Published
- 2017
42. Thermomechanical Stability of Nanostructured Unalloyed Titanium
- Author
-
V. I. Betekhtin, Yu. R. Kolobov, I. N. Kuz’menko, E. A. Erubaev, and S. S. Manokhin
- Subjects
Materials science ,General Physics and Astronomy ,chemistry.chemical_element ,Nanostructured titanium ,02 engineering and technology ,Atmospheric temperature range ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,0104 chemical sciences ,chemistry ,Transmission electron microscopy ,Composite material ,0210 nano-technology ,Titanium - Abstract
The paper presents the experimental results on thermomechanical stability of the structure and the evolution of microstructure of the type ВТ1-0 nanostructured titanium. The cyclic tests are performed within the temperature range of 30–350°С.
- Published
- 2017
43. Effect of ultrasonic treatment on the structure and microhardness of ultrafine grained nickel processed by high pressure torsion
- Author
-
N. Yu. Parkhimovich, Yu. R. Zagidullina, A. A. Mukhametgalina, Yu. V. Tsarenko, V. V. Rubanik, Alexander P. Zhilyaev, A. A. Samigullina, A. A. Nazarov, and S. N. Sergeyev
- Subjects
010302 applied physics ,Materials science ,Torsion (mechanics) ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Indentation hardness ,Nickel ,chemistry ,High pressure ,0103 physical sciences ,General Materials Science ,Ultrasonic sensor ,Composite material ,0210 nano-technology - Published
- 2017
44. Study of the Structure of Crater at the Surface of 12Cr18Ni10Ti Steel Irradiated by High-Power Pulsed Ion Beam
- Author
-
G. V. Potemkin, G. E. Remnev, M. V. Zhidkov, A. E. Ligachev, Yu. R. Kolobov, and S. S. Manokhin
- Subjects
010302 applied physics ,Materials science ,Microscope ,Ion beam ,Scanning electron microscope ,General Engineering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Focused ion beam ,law.invention ,Impact crater ,law ,Transmission electron microscopy ,0103 physical sciences ,General Materials Science ,Composite material ,0210 nano-technology ,Layer (electronics) - Abstract
The topography of surface layers of 12Cr18Ni10Ti (AISI 321) steel after pulsed high-power Cn+ ion beams irradiation was investigated by scanning electron microscopy. A thin foil was prepared from the cross section of a crater with the use of a focused ion beam in the column of a two-beam electron-ion microscope. The microstructure and chemical composition of the crater were studied by transmission electron microscopy. It is shown that the near-surface layer (~2 μm in depth) of the crater is represented by an area of columnar grains elongated in the direction of the surface. Under the layer of columnar grains, the region with equiaxial submicrocrystalline grains is situated.
- Published
- 2018
45. Coarse-grained and ultrafine-grained titanium high-temperature creep
- Author
-
S S Manohin, V. I. Betekhtin, M. V. Narykova, Yu R Kolobov, A. G. Kadomtsev, and A Yu Tokmacheva
- Subjects
History ,Materials science ,Creep ,chemistry ,Metallurgy ,chemistry.chemical_element ,Computer Science Applications ,Education ,Titanium - Abstract
The publication describes the study of durability in tensile creep of VT1-0 commercial titanium in its two states-coarse-grained and ultrafine-grained. It is shown that the best temperature for log-term testing is 350°C. At this temperature, the ultrafine-grained titanium structure remains stable both during free annealing and durability testing. The obtained data enable retrieving the difference in fracture initiation energies for titanium in its coarse-grained and ultrafine-grained states.
- Published
- 2020
46. A Simplified Method for Analytic Calculations of Nonstationary Temperature Fields in Problems Related to Heat Curing of Elastomer Coatings on Fabric Substrates
- Author
-
A. A. Avaev and Yu. R. Osipov
- Subjects
Work (thermodynamics) ,Heat curing ,Materials science ,General Chemical Engineering ,Energy Engineering and Power Technology ,Mechanics ,Elastomer ,law.invention ,Fuel Technology ,Thermal conductivity ,Geochemistry and Petrology ,law ,Heat exchanger ,Cartesian coordinate system ,Heat equation ,Polar coordinate system - Abstract
The work is concerned with analytic calculations of heat exchange in processes of heat curing. The calculations of the temperature fields are based on replacement of the polar coordinates by Cartesian coordinates. This type of replacement significantly simplifies the calculations. The precision of the proposed method for engineering applications is quite high.
- Published
- 2016
47. Shock-wave-induced grain refinement and phase state modification in coarse-grained and nanocrystalline titanium
- Author
-
Yu. E. Kudymova, R. A. Andrievskii, S. S. Manokhin, A. A. Golyshev, V. I. Betekhtin, A. M. Molodets, Yu. R. Kolobov, and A. Yu. Kolobova
- Subjects
010302 applied physics ,Shock wave ,Range (particle radiation) ,Materials science ,Physics and Astronomy (miscellaneous) ,Scanning electron microscope ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Compression (physics) ,01 natural sciences ,Shock (mechanics) ,chemistry ,Phase (matter) ,0103 physical sciences ,Crystallite ,Composite material ,0210 nano-technology ,Titanium - Abstract
We have experimentally studied the structure and phase variations in polycrystalline titanium stimulated by stepwise shock compression at pressures up to 40 GPa with subsequent unloading. The experiments were performed on samples of commercial titanium (VT1-0 grade) in a broad range of initial grain sizes (0.2–50 μm). The phenomenon of grain refinement and phase composition variation in titanium under stepwise shock-wave action has been studied by transmission and scanning electron microscopy techniques. Specific features of these changes are discussed.
- Published
- 2016
48. Properties of thick galvanic steel coatings
- Author
-
Yu. R. Kopylov
- Subjects
Repair processes ,Materials science ,Mechanical Engineering ,Iron chloride ,Conversion coating ,Metallurgy ,Hardening (metallurgy) ,Galvanic cell ,Electrolyte ,Coating deposition ,Industrial and Manufacturing Engineering - Abstract
The properties of thick steel coatings applied galvanically with mechanical action in different conditions in an electrolyte flux are investigated; the electrolyte is based on iron chloride. On the basis of the results, the utility of this process in repairing large and expensive worn components is assessed.
- Published
- 2016
49. Pulsed ion beam induced changes in a submicrocrystalline structure of the near surface layers of austenite steel
- Author
-
G. V. Potemkin, G. E. Remnev, E. V. Golosov, A. E. Ligachev, Yu. R. Kolobov, and M. V. Zhidkov
- Subjects
Equiaxed crystals ,Austenite ,Surface (mathematics) ,Materials science ,Ion beam ,General Engineering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Ion ,Crystallography ,General Materials Science ,Surface layer ,Irradiation ,Composite material ,0210 nano-technology ,Grain structure - Abstract
The topography and structure of near surface layers of submicrocrystalline austenite steel 12Kh18N10T after pulsed irradiation with C+ and H+ ions were investigated. Ion beam irradiation resulting in modification of the near surface layer and formation of a structure close to an equiaxed ultrafine grain structure with a high fraction of high-angle boundaries were shown.
- Published
- 2016
50. Recrystallization behavior of submicrocrystalline titanium
- Author
-
E. A. Erubaev, M. B. Ivanov, S. S. Manokhin, and Yu. R. Kolobov
- Subjects
010302 applied physics ,Materials science ,Scanning electron microscope ,General Chemical Engineering ,Metallurgy ,Kinetics ,Metals and Alloys ,Recrystallization (metallurgy) ,chemistry.chemical_element ,02 engineering and technology ,Activation energy ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,01 natural sciences ,Inorganic Chemistry ,chemistry ,0103 physical sciences ,Materials Chemistry ,Grain boundary diffusion coefficient ,Thermal stability ,0210 nano-technology ,Titanium - Abstract
The recrystallization kinetics in submicrocrystalline titanium (Grade 4) have been studied in a wide temperature range by transmission and scanning electron microscopy. We have assessed kinetic laws, evaluated the activation energy for the recrystallization process, and examined the mechanism of the process in different temperature ranges.
- Published
- 2016
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