scholarly journals On the question of finding a universal mechanism for the transmission of sound wave energy in iron during heating and deformation

2021 ◽  
Vol 2094 (2) ◽  
pp. 022018
Author(s):  
Stepan A Yurchenko
Keyword(s):  
Theoretical Analysis ◽  
Elastic Deformation ◽  
Sound Wave ◽  
Wave Energy ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Ultrasound Wave ◽  
Natural Vibration Frequency ◽  
New Model ◽  
Ultrasound Speed

Abstract The paper presents a theoretical analysis of the experimental data on the ultrasound speed change in iron during heating and elastic deformation. The mathematical models proposed for assessing the change in the ultrasound speed based on the “adiabatic approximation” method do not explain, using one model, the change in the ultrasound speed in iron during heating and elastic deformation. During theoretical analysis, a new model of ultrasound wave transmission has been proposed, in which the wave energy propagates in the volume of the interatomic bond, namely in the loop, which is formed by the “collectivization” of valence electrons located in the outer orbit of atoms. The new model explains why with an increase in the interatomic distance a, the crystal lattice parameter, and an increase in the natural vibration frequency of atoms Vat during heating and elastic deformation, in one case (heating), the speed of the sound wave decreases, but in the other case (elastic deformation), the speed of the wave increases with a general decrease in the temperature of the rod.

Structure and properties of rails after extremely long-term operation

2020 ◽  
pp. 30-39 ◽  
Author(s):  
Yu. F. Ivanov ◽  
V. E. Gromov ◽  
V. E. Kormyshev ◽  
A. M. Glezer
Keyword(s):  
Surface Layer ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Subgrain Structure ◽  
Structure And Properties ◽  
Term Operation ◽  
Head Section ◽  
Structure Phase ◽  
Defective Surface

The paper reveals regularities and mechanisms of structure-phase states and properties formation of of differentially hardened 100-m rails of DT 350 category after the passed tonnage of 1411 mln. tons brutto. The formation of highly defective surface layer with nanosize (40–50 nm) grain-subgrain structure of pearlite colonies and submicrocrystal (150–250 nm) structure grains with structure free ferrite is detected. The change of hardness, microhardness, crystal lattice parameter, microdistorsion level, scalar and excess dislocation density on the rails head section are analyzed. The possible mechanisms of cementite plates’ transformation at extremely long-term operation are discussed.

Peierls “Washboard” Controls Dynamics of the Domain Walls in Molecular Ferrimagnets

2015 ◽  
Vol 233-234 ◽  
pp. 55-59
Author(s):  
Marina Kirman ◽  
Artem Talantsev ◽  
Roman Morgunov
Keyword(s):  
Domain Wall ◽  
Crystal Lattice ◽  
Domain Walls ◽  
Low Frequency ◽  
Domain Wall Motion ◽  
Lattice Parameter ◽  
Structural Defects ◽  
Crystal Lattice Parameter ◽  
Wall Width ◽  
Debye Relaxation

The magnetization dynamics of metal-organic crystals has been studied in low frequency AC magnetic field. Four modes of domain wall motion (Debye relaxation, creep, slide and over - barrier motion (switching)) were distinguished in [MnII(H(R/S)-pn)(H2O)] [MnIII(CN)6]⋅2H2O crystals. Debye relaxation and creep of the domain walls are sensitive to Peierls relief configuration controlled by crystal lattice chirality. Structural defects and periodical Peierls potential compete in the damping of the domain walls. Driving factor of this competition is ratio of the domain wall width to the crystal lattice parameter.

scholarly journals The effect of antimony presence in anodic copper on kinetics and mechanism of anodic dissolution and cathodic deposition of copper

2008 ◽  
Vol 44 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Z.D. Stankovic ◽  
V. Cvetkovski ◽  
M. Vukovic
Keyword(s):  
Anodic Dissolution ◽  
Single Pulse ◽  
Pulse Method ◽  
Sulfate Solution ◽  
Electrode Reaction ◽  
Xrd Analysis ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Cathodic Deposition ◽  
Anode Copper

The influence of the presence of Sb atoms, as foreign metal atoms in anode copper, on kinetics, and, on the mechanism of anodic dissolution and cathodic deposition of copper in acidic sulfate solution has been investigated. The galvanostatic single-pulse method has been used. Results indicate that presence of Sb atoms in anode copper increase the exchange current density as determined from the Tafel analysis of the electrode reaction. It is attributed to the increase of the crystal lattice parameter determined from XRD analysis of the electrode material.

scholarly journals The Effect of High-Intensity Electron Beam on the Crystal Structure, Phase Composition, and Properties of Al–Si Alloys with Different Silicon Content

2021 ◽  
Vol 22 (1) ◽  
pp. 129-157
Author(s):  
D. V. Zaguliaev ◽  
S. V. Konovalov ◽  
Yu. F. Ivanov ◽  
V. E. Gromov ◽  
V. V. Shlyarov ◽  
...  
Keyword(s):  
Solid Solution ◽  
Electron Beam ◽  
Phase Composition ◽  
Crystal Lattice ◽  
High Intensity ◽  
Materials Science ◽  
Lattice Parameter ◽  
Crystal Lattice Parameter ◽  
Material Surface ◽  
Modified Layer

The study deals with the element–phase composition, microstructure evolution, crystal-lattice parameter, and microdistortions as well as the size of the coherent scattering region in the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys irradiated with the high-intensity electron beam. As revealed by the methods of x-ray phase analysis, the principal phases in untreated alloys are the aluminium-based solid solution, silicon, intermetallics, and Fe2Al9Si2 phase. In addition, the Cu9Al4 phase is detected in Al–10.65Si–2.11Cu alloy. Processing alloys with the pulsed electron beam induces the transformation of lattice parameters of Al–10.65Si–2.11Cu (aluminium-based solid solution) and Al–5.39Si–1.33Cu (Al1 and Al2 phases). The reason for the crystal-lattice parameter change in the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys is suggested to be the changing concentration of alloying elements in the solid solution of these phases. As established, if a density of electron beam is of 30 and 50 J/cm2, the silicon and intermetallic compounds dissolve in the modified layer. The state-of-the-art methods of the physical materials science made possible to establish the formation of a layer with a nanocrystalline structure of the cell-type crystallization because of the material surface irradiation. The thickness of a modified layer depends on the parameters of the electron-beam treatment and reaches maximum of 90 µm at the energy density of 50 J/cm2. According to the transmission (TEM) and scanning (SEM) electron microscopy data, the silicon particles occupy the cell boundaries. Such changes in the structural and phase states of the materials response on their mechanical characteristics. To characterize the surface properties, the microhardness, wear parameter, and friction coefficient values are determined directly on the irradiated surface for all modification variants. As shown, the irradiation of the material surface with an intensive electron beam increases wear resistance and microhardness of the Al–10.65Si–2.11Cu and Al–5.39Si–1.33Cu alloys.

An Analysis of a Stationary Pneumatic Wave-Energy Converter

1975 ◽  
Vol 97 (3) ◽  
pp. 1015-1019 ◽  
Author(s):  
Michael E. McCormick
Keyword(s):  
Theoretical Analysis ◽  
Energy Conversion ◽  
Wave Height ◽  
Wave Energy ◽  
Power Output ◽  
Peak Power ◽  
Peak Power Output ◽  
Wave Energy Conversion ◽  
Energy Converter ◽  
Resonant Period

A theoretical analysis of a stationary pneumatic wave-energy conversion device is presented. Results obtained from the analysis show that the power converted is proportional to the cube of the wave height, producing a maximum time-averaged power per wave period of 25 kw for a 20-ft (6.096 m) diameter unit located in a 3-ft (0.9144 m) sea. The device can be adjusted for purposes of efficiency in any sea spectrum by simply changing the draft (length of the centerpipe) of the unit. The peak power output of the device occurs at a period similar to the resonant period of a surge chamber.

Effect of Couple-Stresses on Force Transfer Between Embedded Microfibers

1967 ◽  
Vol 1 (2) ◽  
pp. 174-187 ◽  
Author(s):  
M.A. Sadowsky ◽  
Y.C. Hsu ◽  
M.A. Hussain
Keyword(s):  
Stress Field ◽  
Couple Stress Theory ◽  
Physical Phenomenon ◽  
Lattice Parameter ◽  
Theory Of Elasticity ◽  
Crystal Lattice Parameter ◽  
Tangential Displacement ◽  
Stress Theory ◽  
Couple Stresses ◽  
Force Transfer

The present investigation is a continuation of the Weitsman problem, reference 1. The investigation is concerned with the nature of the stress field which develops in the presence of couple- stresses in composite material formed of microfibers embedded in a filler substance. The case is considered when one row consists of an infinitely long microfiber, while the second row is composed of two semi- infinite microfibers. An exact solution, based on a two-dimensional theory of elastic ity with inclusion of couple-stresses is obtained for the stress field which is activated by giving the two semi-infinite microfibers a tangential displacement of separation. The couple-stress theory gives a better representation of the actual physical phenomenon than the classical theory of elasticity. This is especially true and essentially important for bodies having a dimension comparable to the crystal lattice parameter of the material. This is believed to be the case with an elastic microfilm in bond with microfibers. The investigation led to results which are at wide variance with the Weitsman solution near x = 0 and the asymptotic solution shows the same trend as reported previously in reference num bered 2 i.e., bonding layers are dominated by boundary layer behavior throughout their entire thickness.

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