Nonstationary Electrochemical Response to the Intermittent Portevin–Le Chatelier Deformation in an Aluminum–Magnesium Alloy

Physics of the Solid State - It has been established that the Portevin–Le Chatelier effect in the AlMg6 aluminum–magnesium alloy deformed in an aqueous medium is accompanied by an...     

Destruction of the Aluminum–Magnesium Alloy under the Influence of Pulsed Laser Radiation against Creep Conditions

Physics of the Solid State - Abstract—Using high-speed video recording, the stages of predestruction and development of a main crack initiated by pulsed infrared laser radiation on the...     

Effect of Pulsed IR Laser Radiation on the Dynamics and Morphology of Deformation Bands in an Aluminum–Magnesium Alloy

The dynamics and morphology of deformation bands under the simultaneous effect of mechanical loading and pulsed IR laser radiation on the surface of in aluminum–magnesium alloy AlMg6 were studied by high-speed video recording. The conditions, under which a laser pulse pierces a through hole with a diameter of an order of magnitude smaller than the thickness of a plane specimen, thus inducing the development of a complicated spatiotemporal structure of deformation bands and a macroscopic jump in the tension diagram, were determined. The morphological transitions associated with the transformation of the type, shape, and spatiostatistical distribution of bands with a change in the laser pulse energy density were revealed. The probable mechanism of this phenomenon was discussed.     

Pressure Dependences of Elastic Constants of AMg6 Aluminum–Magnesium Alloy and n-AMg6/С60 Nanocomposite Alloy

The ultrasonic study results for dependence of the elastic wave velocities and second-order elasticity coefficients of the polycrystalline aluminum alloy AMg6 and its nanocomposite n-AMg6/C₆₀ on hydrostatic pressure up to 1.6 GPa have been described. The ultrasonic research has been carried out using a highpressure ultrasonic piezometer based on the piston-cylinder device. The pressure derivatives of the secondorder elastic constants of these materials established in the present study have been compared with the results of the third-order elastic constants measurements of the test alloys using the Thurston–Brugger method. Involving available literature data, we determined the relationships between the pressure derivatives of the second-order elastic constants of the AMg6 alloy and the Mg-content and nanostructuring.

     

Role of the Solid–Aqueous Medium Interface in Transferring Light-Induced Excitation of Silicon

Technical Physics - An effect has been discovered that irradiation of a silicon sample by light changes the properties of another silicon sample several centimeters away from the former. This...     

Influence of Chitosan on Orientation–Micellar Ordering of the Pluronic F-127 Gel Phase in an Aqueous Medium

Optics and Spectroscopy - The influence of chitosan on orientation–micellar association of Pluronic F-127 in an aqueous medium in the temperature range of 4–37°C has been studied...     

Paramagnetic Mn Antisite Defects in Nanoceramics of Aluminum–Magnesium Spinel

Physics of the Solid State - The effect of structure and size parameters on the formation of intrinsic and impurity paramagnetic centers in nanoceramics of aluminum–magnesium spinel is...     

Synthesis and Investigation of Magnesium–Aluminum Nanopowders and Ceramics Activated by Copper

Technical Physics - Nanopowders of two crystalline phases, magnesium–aluminum spinel (98 wt %), and cuprite (2 wt %) have been obtained by laser evaporation of a solid target, which...     

Kinetics and Phase Transformations during the Decomposition of Supersaturated Solid Solutions of Magnesium in Mg–Dy–Sm Alloys

Kinetics and phase transformations are studied for the previously unconsidered decomposition of supersaturated solid solution in magnesium-based alloys Mg–Dy–Sm. The decomposition of solid solution slows when there is an increase in % Dy: % Sm ratio in the alloys. Mg–Sm and Mg–Dy alloys grow harder when Dy and Sm are added to them, respectively. Products of decomposition in ternary Mg–Dy–Sm alloys are the same as in binary alloys Mg–Dy and Mg–Sm but contain combinations of Dy and Sm.     

Wear and Coefficient of Friction of a Supermodified Hypereutectic Aluminum–Silicon Alloy

Technical Physics - The friction coefficient and the wear of a hypereutectic aluminum alloy with 15 wt % silicon and a supermodified eutectic structure without primary silicon crystals, obtained by...     

“Magnetic Memory” in Plasticity of an Aluminum Alloy with Iron Inclusions

Physics of the Solid State - This article is devoted to the effect of a magnetic field of 0.7 T on the state of an aluminum alloy whose creep increases after exposing to a magnetic field,...     

Special Aspects of the Surface Scale Growth during Oxidation of V–Cr–Ta–Zr Alloy in Air

Russian Physics Journal - The results of a study of features of the surface scale growth on the V–Cr–Ta–Zr vanadium alloy specimens during short-term oxidation in air are...     

Effect of Laser Processing on Strength and Portevin–Le Chatelier Serrated Deformation of Aluminum Alloy

Physics of the Solid State - The effect of surface processing by laser IR radiation on strength and Portevin–Le Chatelier serrated deformation of AlMg6 aluminum–magnesium alloy is...     

Electrochemical Role of Transition Metals in Sn–Fe Alloy Revealed by Operando Magnetometry

As promising materials, alloy-type anode materials have been intensively investigated in both academia and industry. To release huge volume expansion during alloying/dealloying process, they are usually doped with transition metals. However, the electrochemical role of transition metals has not been fully understood. Here,pure Sn₃Fe films were deposited by sputtering, and the electrochemical mechanism was systematically investigated by operando magnetometry. We confirmed that Fe parti...     

Dynamics of a Lüders Band and Destruction of an Aluminum-Magnesium Alloy,Initiated by a Stress Concentrator

Spatio-temporal localization of deformation and the rupture of the aluminum-magnesium AlMg6 alloy, initiated by a geometrical stress concentrator, are studied in situ by video recording at a speed of 500 to 20000 frames/s. It is established that a stress concentrator in the form of a small notch with a depth about 1% of the width of a flat specimen is an attractor of bands of macrolocalized plastic deformation, starting from a Lüders band and ending with the start of the main crack. The key role of intersecting deformation macrobands in the development of the main crack is revealed. Possible micromechanisms of viscous destruction associated with the dynamics of the intersection of deformation bands are discussed.     

Inelasticity and Nanostructured Dislocation Deformation of Aluminum–Silicon Alloy with a Supermodified Eutectic Structure

Technical Physics - Young’s modulus and the logarithmic decrement of oscillations at a frequency of ~100 kHz as well as the subgrain size and residual stresses in the strontium modified alloy...     

Temperature and Concentration Dependences of the Landau–Placzek Ratio in Aqueous Solutions of γ-Picoline

Optics and Spectroscopy - Ratios of the intensities of the fine-structure components at molecular light scattering (Landau–Placzek ratios) have been investigated depending on the...     

Scattering of an Acoustic Field by Refraction–Density Inhomogeneities with a Small Wave Size and Solution of the Problem of Direct Scattering in an Inhomogeneous Medium

The paper considers acoustic wave scattering by inhomogeneities with a small wave size using the Green’s function apparatus, which makes it possible universally to take into account both the refraction and density components of an inhomogeneity. Estimates for the multipole components of a field scattered by a nonresonance inhomogeneity are presented. For an inhomogeneity with small dimensions, it suffices to consider only monopole and dipole scattering. These conclusions are confirmed by an analysis of the field scattered by a circular cylinder with a small wave radius. The results are used to numerically simulate a Lippmann–Schwinger equation. The form of the discretized matrix Green’s function for identical values of the spatial arguments is presented. This makes it possible to take into account multiple scattering processes within a discretization element with a small wave size. Its use automatically fulfills the relations between the phase and amplitude of secondary acoustic field sources.