Pub Date : 2024-05-28DOI: 10.1007/s11182-024-03178-1
A. S. Grigoriev, E. V. Shilko
The paper is devoted to a study of factors that provide the nonlinear mechanical influence of pore fluid on the stress state, strength, and fracture of permeable brittle materials. Two key factors are considered: pore pressure and viscous stresses in the interstitial fluid. Using a coupled dynamic model implemented in the numerical method of homogeneously deformable discrete elements, we verified for the first time that Stefan’s viscous stress is responsible for the nontrivial and widely discussed effect of a significant increase in the dynamic strength of brittle solids in a fluid-saturated state compared to the dry state. Considering watered high-strength concrete, a quantitative estimate of the dimensionless factor of Stefan’s stress was derived. The contributions of shearing and tearing-off fracture mechanisms to the total damage of a concrete sample under uniaxial compression with different strain rates are analyzed.
{"title":"An Interplay Between the Weakening and Strengthening Effects of Interstitial Water on the Strength of Porous Brittle Solids","authors":"A. S. Grigoriev, E. V. Shilko","doi":"10.1007/s11182-024-03178-1","DOIUrl":"https://doi.org/10.1007/s11182-024-03178-1","url":null,"abstract":"<p>The paper is devoted to a study of factors that provide the nonlinear mechanical influence of pore fluid on the stress state, strength, and fracture of permeable brittle materials. Two key factors are considered: pore pressure and viscous stresses in the interstitial fluid. Using a coupled dynamic model implemented in the numerical method of homogeneously deformable discrete elements, we verified for the first time that Stefan’s viscous stress is responsible for the nontrivial and widely discussed effect of a significant increase in the dynamic strength of brittle solids in a fluid-saturated state compared to the dry state. Considering watered high-strength concrete, a quantitative estimate of the dimensionless factor of Stefan’s stress was derived. The contributions of shearing and tearing-off fracture mechanisms to the total damage of a concrete sample under uniaxial compression with different strain rates are analyzed.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141171079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-28DOI: 10.1007/s11182-024-03176-3
V. E. Gromov, A. I. Potekaev, A. P. Semin, E. A. Kolubaev, P. S. Mogilnikov, Yu. F. Ivanov, S. V. Panin, S. V. Borovsky, I. Yu. Litovchenko, B. A. Kornienkov
Using the methods of advanced physical materials science, the structural-phase states and properties of an ~80 μm-thick ribbon, made from a FeCoNiSiB high-entropy alloy of a non-equiatomic composition by ultrarapid quenching from melt, are studied. After the melt spinning the ribbon is in an X-ray amorphous state and demonstrates high strength and low plasticity. Anisotropy of its tribological properties is revealed. A differential scanning calorimetry of the ribbon is performed and its magnetic properties are evaluated.
利用先进的物理材料科学方法,研究了由非等原子成分的铁钴镍硅铍高熵合金通过熔体超速淬火制成的约 80 μm 厚的带状材料的结构相态和性能。熔融纺丝后,带状材料处于 X 射线非晶态,具有高强度和低塑性。其摩擦学特性的各向异性也得到了揭示。对色带进行了差示扫描量热分析,并对其磁性能进行了评估。
{"title":"Structure and Properties of a Ribbon from FeCoNiSiB High-Entropy Alloy","authors":"V. E. Gromov, A. I. Potekaev, A. P. Semin, E. A. Kolubaev, P. S. Mogilnikov, Yu. F. Ivanov, S. V. Panin, S. V. Borovsky, I. Yu. Litovchenko, B. A. Kornienkov","doi":"10.1007/s11182-024-03176-3","DOIUrl":"https://doi.org/10.1007/s11182-024-03176-3","url":null,"abstract":"<p>Using the methods of advanced physical materials science, the structural-phase states and properties of an ~80 μm-thick ribbon, made from a FeCoNiSiB high-entropy alloy of a non-equiatomic composition by ultrarapid quenching from melt, are studied. After the melt spinning the ribbon is in an X-ray amorphous state and demonstrates high strength and low plasticity. Anisotropy of its tribological properties is revealed. A differential scanning calorimetry of the ribbon is performed and its magnetic properties are evaluated.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141166966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-28DOI: 10.1007/s11182-024-03190-5
S. Srivastava, S. K. Sarangi, S. P. Singh
This study investigates water absorption and porosity in the chitosan matrix reinforced with nano-biosilica, bamboo fiber, and jute fiber used for long bone material implants. The water absorption tests reveal distinct patterns in CP, CF, C1, C2, and C3 biocomposites, thereby highlighting the influence of their composition. Notably, 1% nano-biosilica reduces water absorption, yet increased nano-silica concentrations lead to heightened porosity. Striking a balance between optimal porosity for osseointegration and mechanical strength is crucial. Hybridization proves effective in mitigating water uptake and porosity. This study advances knowledge in biomaterial intricacies, providing crucial insights for tailored implant design.
{"title":"Investigation of Water Absorption and Porosity of Nano-Biosilica, Jute, and Bamboo Fiber-Reinforced Chitosan Biocomposite Materials","authors":"S. Srivastava, S. K. Sarangi, S. P. Singh","doi":"10.1007/s11182-024-03190-5","DOIUrl":"https://doi.org/10.1007/s11182-024-03190-5","url":null,"abstract":"<p>This study investigates water absorption and porosity in the chitosan matrix reinforced with nano-biosilica, bamboo fiber, and jute fiber used for long bone material implants. The water absorption tests reveal distinct patterns in CP, CF, C1, C2, and C3 biocomposites, thereby highlighting the influence of their composition. Notably, 1% nano-biosilica reduces water absorption, yet increased nano-silica concentrations lead to heightened porosity. Striking a balance between optimal porosity for osseointegration and mechanical strength is crucial. Hybridization proves effective in mitigating water uptake and porosity. This study advances knowledge in biomaterial intricacies, providing crucial insights for tailored implant design.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141166971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-28DOI: 10.1007/s11182-024-03175-4
E. G. Komarova, E. A. Kazantseva, E. B. Akimova, P. V. Uvarkin
The comprehensive approach using both pull-off tensile and scratch tests provided a detailed understanding of the adhesion and cohesion properties of the 3D-porous calcium phosphate (CaP) coatings deposited on a Ti substrate by the ultrasound-assisted micro-arc oxidation (UMAO) method. Using the pull-off tensile test which takes into account tensile stresses directed normally to the coating surface, it was found that the ultrasound (US) employing during the the micro-arc oxidation (MAO) process led to a slight decrease in the adhesion of the coating to the substrate from 23.4 to 19.3 MPa as well as to a change in the failure mechanism from the cohesive type characteristic for the control MAO coatings to the adhesive-cohesive type for the UMAO coatings. On the contrary, the results of the scratch test, which takes into account compressive stresses directed normally and tangentially to the coating surface, showed that the US employed during the MAO process led to an increase in the critical loads LC2 and LC3 to 6.7 and 30.6 N, respectively, promoting the adhesive-cohesive and adhesive failures of the coatings. Thus, the US employed during the MAO process led to an increase in the critical shear stresses of the UMAO coatings, thereby increasing their abrasion resistance.
利用拉脱拉伸试验和划痕试验的综合方法详细了解了通过超声辅助微弧氧化(UMAO)方法沉积在钛基底上的三维多孔磷酸钙(CaP)涂层的附着力和内聚力特性。拉伸试验考虑的是正常指向涂层表面的拉伸应力,使用拉伸试验发现,在微弧氧化(MAO)过程中使用超声波(US)导致涂层与基底的附着力从 23.4 兆帕轻微下降到 19.3 兆帕,失效机制也从对照 MAO 涂层的内聚型特征转变为 UMAO 涂层的粘附型特征。相反,考虑到正常方向和切线方向对涂层表面的压应力的划痕试验结果表明,在 MAO 过程中使用的 US 导致临界载荷 LC2 和 LC3 分别增加到 6.7 和 30.6 N,促进了涂层的粘合-内聚型和粘合型失效。因此,MAO 工艺中使用的 US 导致 UMAO 涂层的临界剪切应力增加,从而提高了其耐磨性。
{"title":"Adhesion and Cohesion of Three-Dimensional Porous Calcium Phosphate Coatings on Titanium Deposited by Ultrasound-Assisted Micro-Arc Oxidation Method","authors":"E. G. Komarova, E. A. Kazantseva, E. B. Akimova, P. V. Uvarkin","doi":"10.1007/s11182-024-03175-4","DOIUrl":"https://doi.org/10.1007/s11182-024-03175-4","url":null,"abstract":"<p>The comprehensive approach using both pull-off tensile and scratch tests provided a detailed understanding of the adhesion and cohesion properties of the 3D-porous calcium phosphate (CaP) coatings deposited on a Ti substrate by the ultrasound-assisted micro-arc oxidation (UMAO) method. Using the pull-off tensile test which takes into account tensile stresses directed normally to the coating surface, it was found that the ultrasound (US) employing during the the micro-arc oxidation (MAO) process led to a slight decrease in the adhesion of the coating to the substrate from 23.4 to 19.3 MPa as well as to a change in the failure mechanism from the cohesive type characteristic for the control MAO coatings to the adhesive-cohesive type for the UMAO coatings. On the contrary, the results of the scratch test, which takes into account compressive stresses directed normally and tangentially to the coating surface, showed that the US employed during the MAO process led to an increase in the critical loads <i>L</i><sub><i>C</i>2</sub> and <i>L</i><sub><i>C</i>3</sub> to 6.7 and 30.6 N, respectively, promoting the adhesive-cohesive and adhesive failures of the coatings. Thus, the US employed during the MAO process led to an increase in the critical shear stresses of the UMAO coatings, thereby increasing their abrasion resistance.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141171075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-28DOI: 10.1007/s11182-024-03170-9
G. P. Grabovetskaya, I. P. Mishin, E. V. Naydenkin, E. N. Stepanova, O. V. Zabudchenko
The development of deformation and fracture in titanium alloy VT22 in the temperature range of 293–823 K is studied in the presence of ~0.1 wt.% hydrogen. It has been shown that the formation of the structure consisting of β-transformed grains with thin lamellar structure and particles of the primary α-phase increases the resistance of the hydrogenated VT22 alloy to localized plastic deformation at the macrolevel and promotes the transition of the alloy fracture from brittle-ductile to ductile during tension at room temperature. At elevated temperatures (653–823 K), the presence of dissolved hydrogen in the solid solution in the VT22 alloy reduces its resistance to localized plastic deformation at the macrolevel and the deformation value to failure.
{"title":"Effect of Hydrogen on the Development of Deformation and Fracture in Titanium Alloy VT22 in the Temperature Range of 293–823 K","authors":"G. P. Grabovetskaya, I. P. Mishin, E. V. Naydenkin, E. N. Stepanova, O. V. Zabudchenko","doi":"10.1007/s11182-024-03170-9","DOIUrl":"https://doi.org/10.1007/s11182-024-03170-9","url":null,"abstract":"<p>The development of deformation and fracture in titanium alloy VT22 in the temperature range of 293–823 K is studied in the presence of ~0.1 wt.% hydrogen. It has been shown that the formation of the structure consisting of β-transformed grains with thin lamellar structure and particles of the primary α-phase increases the resistance of the hydrogenated VT22 alloy to localized plastic deformation at the macrolevel and promotes the transition of the alloy fracture from brittle-ductile to ductile during tension at room temperature. At elevated temperatures (653–823 K), the presence of dissolved hydrogen in the solid solution in the VT22 alloy reduces its resistance to localized plastic deformation at the macrolevel and the deformation value to failure.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141171101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-28DOI: 10.1007/s11182-024-03168-3
M. M. Mikhailov, S. A. Yur’ev, A. N. Lapin, V. A. Goronchko
The paper studies the electron irradiation at an energy of 30 keV affecting the diffuse-reflectance spectra and integrated absorption coefficient of solar irradiance of the micron-sized mZnO powder modified by adding nY2O3 nanoparticles in the amount of 0.1 to 10 wt.%. The best content of nanoparticles is found to be 3 wt.%, when the diffuse-reflectance spectra and the integrated absorption coefficient of the modified powder are 1.41 times lower than in the initial powder. It is shown that free electrons forming during the powder irradiation, make the highest contribution to the powder degradation.
{"title":"Radiation Resistance of Optical Nanopowder Modified by Y2O3 Particles","authors":"M. M. Mikhailov, S. A. Yur’ev, A. N. Lapin, V. A. Goronchko","doi":"10.1007/s11182-024-03168-3","DOIUrl":"https://doi.org/10.1007/s11182-024-03168-3","url":null,"abstract":"<p>The paper studies the electron irradiation at an energy of 30 keV affecting the diffuse-reflectance spectra and integrated absorption coefficient of solar irradiance of the micron-sized mZnO powder modified by adding nY<sub>2</sub>O<sub>3</sub> nanoparticles in the amount of 0.1 to 10 wt.%. The best content of nanoparticles is found to be 3 wt.%, when the diffuse-reflectance spectra and the integrated absorption coefficient of the modified powder are 1.41 times lower than in the initial powder. It is shown that free electrons forming during the powder irradiation, make the highest contribution to the powder degradation.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141171200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-27DOI: 10.1007/s11182-024-03171-8
N. V. Bukrina, A. G. Knyazeva
The paper proposes a two-dimensional thermokinetic model of the composite synthesis process in the mode of dynamic thermal explosion taking into account the structurization of the synthesis product. Structurization in the model is understood as a transition from amorphous to crystalline state. The model takes into account the heating of the reactor walls by thermal radiation from the device, the temperature of which can vary at different rates. Chemical reactions are described by a summary scheme that corresponds to the synthesis of Ni3Al composite. The kinetic law takes into account a possible strong inhibition of the rate of the reaction with the accumulation of the synthesis product, which is typical for reactions controlled by diffusion at the particle level. The effective thermophysical properties of the components of mixture and reaction products in the reactor depend on the properties of the constituents of the initial mixture and the fraction of reaction product. The properties of the latter also depend on the degree of structurization. The structurization process is described by a special additional parameter whose evolution is modeled by a reversible reaction. It is assumed that the structurization process starts from the moment of product appearance and continues during the cooling of the system. It is shown that synthesis results in the formation of a composite containing the initial components and the reaction product with the matrix partly in the amorphous state and partly in the structured state. The dynamics of synthesis and structurization are influenced by heating conditions and reactor size.
{"title":"Modeling of Volumetric Synthesis of Composite with Regard the Subsequent Structurization","authors":"N. V. Bukrina, A. G. Knyazeva","doi":"10.1007/s11182-024-03171-8","DOIUrl":"https://doi.org/10.1007/s11182-024-03171-8","url":null,"abstract":"<p>The paper proposes a two-dimensional thermokinetic model of the composite synthesis process in the mode of dynamic thermal explosion taking into account the structurization of the synthesis product. Structurization in the model is understood as a transition from amorphous to crystalline state. The model takes into account the heating of the reactor walls by thermal radiation from the device, the temperature of which can vary at different rates. Chemical reactions are described by a summary scheme that corresponds to the synthesis of Ni<sub>3</sub>Al composite. The kinetic law takes into account a possible strong inhibition of the rate of the reaction with the accumulation of the synthesis product, which is typical for reactions controlled by diffusion at the particle level. The effective thermophysical properties of the components of mixture and reaction products in the reactor depend on the properties of the constituents of the initial mixture and the fraction of reaction product. The properties of the latter also depend on the degree of structurization. The structurization process is described by a special additional parameter whose evolution is modeled by a reversible reaction. It is assumed that the structurization process starts from the moment of product appearance and continues during the cooling of the system. It is shown that synthesis results in the formation of a composite containing the initial components and the reaction product with the matrix partly in the amorphous state and partly in the structured state. The dynamics of synthesis and structurization are influenced by heating conditions and reactor size.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141166986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-27DOI: 10.1007/s11182-024-03186-1
P. A. Sukhar’, A. A. Orlov
The paper presents calculations of the process parameters of the chemical isotope exchange with a thermal flow reversal in the BF3–C6H5OCH3 system and engineering data for rectifying columns for its implementation. It is shown that the calculated parameters are in good agreement with those found the literature. The best engineering data are obtained for rectifying columns intended for the production of enriched (96 wt.% 10B enrichment) boron in the amount of 2 and 4 tons per year.
{"title":"Boron Isotope Separation Using Chemical Isotope Exchange with Thermal Flow Reversal","authors":"P. A. Sukhar’, A. A. Orlov","doi":"10.1007/s11182-024-03186-1","DOIUrl":"https://doi.org/10.1007/s11182-024-03186-1","url":null,"abstract":"<p>The paper presents calculations of the process parameters of the chemical isotope exchange with a thermal flow reversal in the BF<sub>3</sub>–C<sub>6</sub>H<sub>5</sub>OCH<sub>3</sub> system and engineering data for rectifying columns for its implementation. It is shown that the calculated parameters are in good agreement with those found the literature. The best engineering data are obtained for rectifying columns intended for the production of enriched (96 wt.% <sup>10</sup>B enrichment) boron in the amount of 2 and 4 tons per year.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141166972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-27DOI: 10.1007/s11182-024-03167-4
I. V. Smirnov, I. A. Ditenberg, V. I. Tolstihin
Using the methods of transmission and scanning electron microscopy, the microstructure of a V–W–Cr–Zr alloy is studied as a function of its plastic deformation value under the condition of high-pressure torsion in the Bridgman anvils. The main stages of structure transformation and the respective mechanisms are identified. It is found out that the grain and defect structure transformation up to e ≈ 1.1 is provided by the dislocation and dislocation-disclination mechanisms, which when combined activate the processes of submicrocrystalline structure formation. The deformation impact in the strain interval from e ≈ 1.1 to e ≈ 3 is characterized by a significant increase in the grain-boundary length. A high strength state is achieved in the course of this deformation, where the dislocation modes of plastic deformation are suppressed. This is accompanied by the activated processes of formation of two-level nanostructured states, wherein the principal mechanism is a quasi-viscous re-orientation by the flows of non-equilibrium point defects. A further increase in the deformation to e ≈ 5.3 gives rise to refinement of the submicrocrystalline grains and formation of two-level nanostructured states in the entire material volume. The main contribution to the grain- and subgrain transformations comes from the disclination and quasi-viscous modes of plastic deformation. At higher strain degrees (e > 5.3), the size of submicrocrystalline grains does not virtually change, and the transformation of two-level nanostructured states makes itself evident in the rotations of some of the fragments of this structure with respect to the other by small angles from tens of fractions of a degree to several degrees. The formation of the submicrocrystalline state is followed by a multiple increase in the microhardness; its values are observed to saturate at e ≈ 3.3.
利用透射电子显微镜和扫描电子显微镜方法,研究了在布里奇曼铁砧高压扭转条件下,V-W-Cr-Zr 合金的微观结构与塑性变形值的函数关系。确定了结构转变的主要阶段和各自的机理。研究发现,在 e ≈ 1.1 时,晶粒和缺陷结构的转变是由位错和位错-偏斜机制实现的,这两种机制结合在一起激活了亚微晶结构的形成过程。在 e ≈ 1.1 到 e ≈ 3 的应变区间内,变形影响的特点是晶界长度显著增加。在这一变形过程中实现了高强度状态,塑性变形的位错模式受到抑制。与此同时,两级纳米结构态的形成过程被激活,其主要机制是通过非平衡点缺陷流的准粘性重新定向。变形进一步增大到 e ≈ 5.3 会导致亚微晶晶粒细化,并在整个材料体积中形成两级纳米结构态。对晶粒和亚晶粒转变的主要贡献来自塑性变形的离散和准粘性模式。在较高的应变度(e > 5.3)下,亚微晶晶粒的尺寸实际上不会发生变化,而两级纳米结构态的转变则表现为这种结构的一些片段相对于另一个片段旋转了几十度到几度不等的小角度。亚微晶态形成后,显微硬度成倍增加;在 e ≈ 3.3 时,显微硬度值达到饱和。
{"title":"Microstructure and Microhardness of V–W–Cr–Zr Alloy Depending on Deformation in Bridgman Anvils","authors":"I. V. Smirnov, I. A. Ditenberg, V. I. Tolstihin","doi":"10.1007/s11182-024-03167-4","DOIUrl":"https://doi.org/10.1007/s11182-024-03167-4","url":null,"abstract":"<p>Using the methods of transmission and scanning electron microscopy, the microstructure of a V–W–Cr–Zr alloy is studied as a function of its plastic deformation value under the condition of high-pressure torsion in the Bridgman anvils. The main stages of structure transformation and the respective mechanisms are identified. It is found out that the grain and defect structure transformation up to e ≈ 1.1 is provided by the dislocation and dislocation-disclination mechanisms, which when combined activate the processes of submicrocrystalline structure formation. The deformation impact in the strain interval from e ≈ 1.1 to e ≈ 3 is characterized by a significant increase in the grain-boundary length. A high strength state is achieved in the course of this deformation, where the dislocation modes of plastic deformation are suppressed. This is accompanied by the activated processes of formation of two-level nanostructured states, wherein the principal mechanism is a quasi-viscous re-orientation by the flows of non-equilibrium point defects. A further increase in the deformation to e ≈ 5.3 gives rise to refinement of the submicrocrystalline grains and formation of two-level nanostructured states in the entire material volume. The main contribution to the grain- and subgrain transformations comes from the disclination and quasi-viscous modes of plastic deformation. At higher strain degrees (e > 5.3), the size of submicrocrystalline grains does not virtually change, and the transformation of two-level nanostructured states makes itself evident in the rotations of some of the fragments of this structure with respect to the other by small angles from tens of fractions of a degree to several degrees. The formation of the submicrocrystalline state is followed by a multiple increase in the microhardness; its values are observed to saturate at e ≈ 3.3.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141173529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper investigates the behavior of the magnon-magnon entanglement in a double cavity-magnon system with optical parametric amplifiers (OPA) and where both cavities are coupled by the photon tunneling process. Using the standard Langevin approach, the explicit expression is suggested for the covariance matrix describing the two magnon modes and further proved by logarithmic negativity, that the steady state of the indirectly coupled magnons is genuinely entangled. Moreover, the best parameters are obtained to achieve the magnon-magnon entanglement. It is shown that the entanglement robustness against the negative effect of the thermal bath can be enhanced by a proper choice of both the cavity-cavity coupling and the OPA gain.
{"title":"Enhancement of Magnon-Magnon Entanglement in a Double Cavity-Magnon System by Optical Parametric Amplifier","authors":"Noureddine Benrass, Abdelkader Hidki, Driss Aoune, Nabil Habiballah","doi":"10.1007/s11182-024-03185-2","DOIUrl":"https://doi.org/10.1007/s11182-024-03185-2","url":null,"abstract":"<p>The paper investigates the behavior of the magnon-magnon entanglement in a double cavity-magnon system with optical parametric amplifiers (OPA) and where both cavities are coupled by the photon tunneling process. Using the standard Langevin approach, the explicit expression is suggested for the covariance matrix describing the two magnon modes and further proved by logarithmic negativity, that the steady state of the indirectly coupled magnons is genuinely entangled. Moreover, the best parameters are obtained to achieve the magnon-magnon entanglement. It is shown that the entanglement robustness against the negative effect of the thermal bath can be enhanced by a proper choice of both the cavity-cavity coupling and the OPA gain.</p>","PeriodicalId":770,"journal":{"name":"Russian Physics Journal","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141173530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}