Materials physics and mechanics

RAR RUS 103-107 FSBEI HPE “Kh.M. Berbekov Kabardino-Balkarian State University” Kozlov

Nalchik, Russia

FSBEI HE “Kh.M. Berbekov Kabardino-Balkarian State University” Dolbin

Nalchik, Russia

The simulation of carbon nanotubes as macromolecular coils: interfacial adhesion Simulation of carbon nanotubes ring-like formations as macromolecular coils was performed within the frameworks of fractal physical chemistry of polymer solutions. The dependence of interfacial adhesion level has been shown in nanocomposites polymer/carbon nanotubes on the indicated formations structure, characterized by its fractal dimension. This treatment correctness was confirmed by nanocomposites reinforcement degree description within the framework of reinforcement molecular theory. 10.18720/MPM.3222017_1 nanocomposite; epoxy polymer; ring-like formation; interfacial adhesion; fractal dimension https://mpm.spbstu.ru/article/2017.55.1/ MPM232_01_kozlov.pdf

RAR RUS 108-116 Institute for Problems of Mechanical Engineering of the RAS Benemanskaya

St.Petersburg, Russia

Institute for Problems of Mechanical Engineering of the RAS Dementev

St.Petersburg, Russia

P-4505-2016 7006034020 0000-0002-2973-8645 Institute of Problems of Mechanical Engineering RAS Kukushkin S.A. sergey,a.kukushkin@gmail.com

St.Petersburg, Russia

Institute for Problems of Mechanical Engineering of the RAS Lapushkin

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Osipov A.V.

St.Petersburg, Russia

Institute for Problems of Mechanical Engineering of the RAS Timoshnev

St.Petersburg, Russia

Carbon-based nanostructure created by Ba and Cs atomic layer deposition on the vicinal 3C-SiC(111) surfaces New type of carbon based nanostructure on the vicinal 3C-SiC(111)-4° and 3CSiC(111)-8° surfaces with adsorbed Ba and Cs nanolayers has been found. The 3C-SiC(111)- 4° (8°) samples were grown by low-defect unstressed nanoscaled films epitaxy method on silicon vicinal substrates. Electronic structure of the 3C-SiC(111)-4° (8°) surfaces and the (Ba, Cs)/3C-SiC(111)-4° (8°) interfaces has been detailed studied in situ in an ultrahigh vacuum by synchrotron-based photoelectron spectroscopy. The C 1s, Si 2p, Ba 4d core levels and valence band spectra were investigated as a function of Ba or Cs submonolayer coverages. A special fine structure of the C 1s core level spectrum was revealed to appear under Ba and Cs adsorption on the vicinal SiC surface only. Drastic change in the C 1s spectrum was ascertained and shown to be originated from the interacting Si vacancy and adsorbed Ba (Cs) atoms initiating both the electron redistribution and surface reconstruction effects with formation of a new type of the C-enriched graphitic-like nanostructure. 10.18720/MPM.3222017_2 silicon carbide on silicon; wide bandgap semiconductors; thin film epitaxy; carbonbased nanostructure; vicinal 3C-SiC(111) surfaces; absorbed Ba and Cs nanolayers; electronic structure https://mpm.spbstu.ru/article/2017.55.2/ MPM232_02_benemanskaya.pdf

RAR RUS 117-122 Altai State Technical University Poletaev Gennady M.

Barnaul, Russia

Siberian State Industrial University Zorya

Novokuznetsk, Russia

Altai State Technical University Medvedeva

Barnaul, Russia

Altai State Technical University Novoselova

Barnaul, Russia

I.I. Polzunov Altai State Technical University Starostenkov

Barnaul, Russia

The study of the interaction of hydrogen impurity with point and linear defects in palladium and nickel The work is devoted to the study of the interaction of hydrogen with point defects (vacancy, bivacancy, trivacancy, stacking fault tetrahedron, intrinsic interstitial atom) and linear (complete and partial edge dislocations, screw dislocation) defects in Pd and Ni by the method of molecular dynamics. The bond energies of the hydrogen impurity with considered defects were obtained. It is shown that the most effective hydrogen traps in Pd and Ni are vacancies and vacancy clusters. The high sorption capacity of vacancies should contribute to significantly effect of their concentration on the overall sorption capacity of the metal, especially for metals such as Ni, for which the energy of absorption by vacancies and vacancy clusters is negative while the absorption energy by a pure crystal is positive. The presence of dislocations and dislocation complexes in Ni, low-angle grain boundaries, according to the obtained data, weakly affects to the sorption ability of the metal in comparison with vacancies and vacancy clusters. 10.18720/MPM.3222017_3 molecular dynamics; metal; hydrogen; point defect; bond energy; absorption energy; dislocation; stacking fault tetrahedron https://mpm.spbstu.ru/article/2017.55.3/ MPM232_03_poletaev.pdf

RAR RUS 123-132 59122315900 0000-0002-1572-2108 Kurukshetra University Kumar Rajneesh

Kurukshetra, India

RTM Nagpur University Manthena

Nagpur, India

RTM Nagpur University Lamba

India

RTM Nagpur University Kedar

Nagpur, India

Generalized thermoelastic axi-symmetric deformation problem in a thick circular plate with dual phase lags and two temperatures In the present work, a thick circular plate with axisymmetric heat supply has been considered. It is assumed that lower and upper surfaces of the plate are traction free. The plate is subjected to an axisymmetric heat supply depending on the radial and axial directions of the cylindrical polar co-ordinate system with symmetry about z-axis. The initial temperature in the thick plate is given by a constant temperature T0 and the heat flux is prescribed on the upper and lower boundary surfaces. Integral transform technique and its inversion is applied to determine displacement components, stresses, conductive temperature and temperature change. The results have been computed numerically and are illustrated graphically. 10.18720/MPM.3222017_4 thermoelastic problem; two-temperatures; dual phase lags; thermal stresses; thick circular plate; integral transform https://mpm.spbstu.ru/article/2017.55.4/ MPM232_04_kumar.pdf

RAR RUS 133-143 Peter the Great St. Petersburg Polytechnic University Markov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Linkov

St.Petersburg, Russia

An effective method to find Green's functions for layered media Layered structure of rocks strongly influences propagation of hydraulic fractures widely used in practice to increase oil and gas production. The paper aims to facilitate modeling of hydraulic fractures. We develop a method to overcome the main difficulty, which arises when modeling fractures in layered systems: the need in building Green's functions for systems of layers. The method employs highly efficient fast Fourier transform (FFT) in frames of the difference equations method. Its key computational parameters are established by studying bench-mark problems. Green's functions with log-type singularity are included into the theory and the algorithm developed. The accuracy of the method and its application are illustrated with numerical examples. 10.18720/MPM.3222017_5 layered structures; Green's function; hydraulic fractures; Fourier transform; boundary element method https://mpm.spbstu.ru/article/2017.55.5/ MPM232_05_markov.pdf

RAR RUS 144-151 Togliatti State University Gryzunova

Togliatti, Russia

Togliatti State University Vikarchuk

Togliatti, Russia

Togliatti State University Gryzunov

Togliatti, Russia

F-1445-2014 7202768874 0000-0003-3738-408X ITMO University Romanov Alexey alexey.romanov@niuitmo.ru

St.Petersburg, Russia

Copper crystals with fragmented structure and developed surface in temperature fields The effect of electrodeposition regimes of copper polycrystalline foils and coatings on their structure, morphology and behavior during subsequent heat treatment is studied. Electrodeposition is carried out with simultaneous mechanical activation of the surface of foils and coatings, which leads both to the materials internal structural changes and to the appearance of features of the surface morphology: the specific faceting of growth terrains, the formation of polyatomic growth steps, and the appearance of crystals (grains) with pentagonal symmetry. The results of changes in the morphology, structure and phase composition of the polycrystalline copper obtained during the heat treatment in oxidizing or inert atmospheres are presented. 10.18720/MPM.3222017_6 electrodeposition; copper polycrystalline foils; structure; morphology https://mpm.spbstu.ru/article/2017.55.6/ MPM232_06_gryzunova.pdf

RAR RUS 152-164 Institute of Problems of Mechanical Engineering RAS Meshcheryakov Yu.I.

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Zhigacheva

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Divakov

St.Petersburg, Russia

K-4577-2013 57384230400 St.Petersburg State University Petrov Yuri y.v.petrov@spbu.ru

St.Petersburg, Russia

Shock-induced structural instabilities and spall-strength of maraging steels The shock-induced structural instability for three kinds of maraging steel is studied with two experimental techniques: Taylor technique and uniaxial strain conditions. Spall strength of steels is shown to be determined by the structural instability threshold under compression at the front of compressive pulse. Microstructure investigation of post-shocked specimens show that structural instability of maraging steel results from two factors: (i) disintegration of strengthen phase created in the process of aging of steel and (ii) shock-induced nucleation of localized austenite inclusions responsible for decrease of yield stress and fragmentation. Dynamic fracture of maraging steels is found to occur along the boundaries between shock-induced austenite laths and rest of the matrix. 10.18720/MPM.3222017_7 shock loading; structural instability; austenite; intermetallide; spallation https://mpm.spbstu.ru/article/2017.55.7/ MPM232_07_mescheryakov.pdf

RAR RUS 165-177 The University of the South Pacific Narayan

Suva, FIJI

The University of the South Pacific Rajeshkannan

Suva, FIJI

Effect of titanium carbide addition on the workability behavior of powder metallurgy aluminum preforms during hot deformation Experimental investigation has been carried out to evaluate the effect of titanium carbide (TiC) addition on the composite aluminium preforms. The hot upsetting of the composite aluminium preforms with varying TiC contents, namely, 1%, 2%, 3% and 4%, and different aspect ratios, namely, 0.2, 0.4 and 0.6, was carried out and the workability behavior of the same was determined. The influence of TiC addition, in the aluminium composite, on the relative density (R), stress ratio parameters, σθ, σeff and σz/σeff and formability stress index was studied. The effects of initial preform geometry and initial theoretical density on the workability behavior have been studied. 10.18720/MPM.3222017_8 workability; stress ratio parameter; formability stress index; relative density; triaxial stress https://mpm.spbstu.ru/article/2017.55.8/ MPM232_08_narayan.pdf

RAR RUS 178-185 ITMO Univesity Kremleva

St.Petersburg, Russia

Ioffe Institute Kirilenko

St.Petersburg, Russia

Ioffe Institute Nikolaev

St.Petersburg, Russia

Ioffe Institute Pechnikov

St.Petersburg, Russia

Ioffe Institute Stepanov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Odnoblyudov

St.Petersburg, Russia

ITMO University V.E. Bougrov

St.Petersburg, Russia

F-1445-2014 7202768874 0000-0003-3738-408X ITMO University Romanov Alexey alexey.romanov@niuitmo.ru

St.Petersburg, Russia

Defects in thin epitaxial layers of (AlхGa1-х)2O3 grown on Al2O3 substrates Gallium oxide is considered as a perspective functional material for a wide range of applications. This includes light emitting devices, high power electronics, gas sensors and catalysts. Investigation of its structural features, particularly, defect structure of the gallium oxide epitaxial layers is crucial for the high quality devices production technology development. This work is focused on the investigation of the defect structure of thin epitaxial layers of (AlхGa1-х)2O3 possessing monoclinic structure grown by hydride vapor phase epitaxy on Al2O3 substrates. Some of the observed plane defects, twins and stacking faults, are shown for the first time. 10.18720/MPM.3222017_9 gallium oxide; twins; stacking faults; dislocations; hydride vapor phase epitaxy; tilted domains; transmission electro microscopy https://mpm.spbstu.ru/article/2017.55.9/ MPM232_09_kremleva.pdf

RAR RUS 186-193 Siberian State Industrial University Sarychev

Novokuznetsk, Russia

Siberian State Industrial University Granovskiy

Novokuznetsk, Russia

Siberian State Industrial University Konovalov

Novokuznetsk, Russia

Siberian State Industrial University Temlyantsev

Novokuznetsk, Russia

Siberian State Industrial University Nevskii

Novokuznetsk, Russia

Siberian State Industrial University Gromov

Novokuznetsk, Russia

Mathematical model of ultrasound transmission in gradient materials synthesized in arc surfacing under contact loading The paper deals with a two-dimensional problem of time-dependent elasticitytheory, examining waves generated on the top layer interface by the source of normal stressesapplied to the top layer interface. Here the lower layer interface is free of stresses. The use is made of integral transformations to relate displacement transforms with stresses on the top layer interface. Exponent power series expansion is obtained for the transform of verticaldisplacements. Analytical approach to each member of the series ensures a precise solution of the problem. Displacement field vs. time dependence on the layer interface has been calculated. The findings are referred to in the process of ultrasound controlling t he layer by finite size sensors. 10.18720/MPM.3222017_10 stress; deformation; strengthened layer; surfacing; ultrasound waves https://mpm.spbstu.ru/article/2017.55.10/ MPM232_10_sarychev.pdf

RAR RUS 194-197 ITMO Univesity Kolodeznyi

St.Petersburg, Russia

Connector Optics LLC Novikov

St.Petersburg, Russia

Connector Optics LLC Gladyshev

St.Petersburg, Russia

ITMO University Rochas

St.Petersburg, Russia

ITMO University Sharipo

St.Petersburg, Russia

Connector Optics LLC Karachinsky

St.Petersburg, Russia

ITMO University Egorov

St.Petersburg, Russia

ITMO University V.E. Bougrov

St.Petersburg, Russia

Study of antireflection coatings for high speed 1.3 -1.55 µm InGaAs/InP PIN photodetector Single layer antireflection coatings have been studied for optimization InGaAs/InP photodetector with normal incident light over the 1300-1550-nm wavelength range. Silicon nitride coatings with various thicknesses were fabricated using plasma enhanced chemical vapor deposition and inductively coupled plasma chemical vapor deposition. The antireflection coating with thickness of 200 nm demonstrated reflection below 10 % at 1550 nm wavelength. 10.18720/MPM.3222017_11 single layer antireflection coating; silicon nitride coating; InGaAs/InP photodetector https://mpm.spbstu.ru/article/2017.55.11/ MPM232_11_kolodeznyi.pdf

RAR RUS 198-206 Togliatti State University Sosnin

Togliatti, Russia

Togliatti State University Turkov

Togliatti, Russia

Togliatti State University M.R. Shafeev

Togliatti, Russia

University of Tartu Shulga

Tartu, Estonia

University of Tartu Kink

Tartu, Estonia

Togliatti State University Vikarchuk

Togliatti, Russia

F-1445-2014 7202768874 0000-0003-3738-408X ITMO University Romanov Alexey alexey.romanov@niuitmo.ru

St.Petersburg, Russia

Synthesis of silver nanochains with a chemical method We describe the method of synthesis of chain-like silver nanowires (nanochains) and find the favorable conditions to fabricate them. The nanochains are processed in the hot ethylene glycol solution with constant stirring in the presence of nickel nanoparticles and polyvinylpyrrolidone 360000 molecules. Silver nanochains consist of straight-linear segments connected end-to-end. The length of straight-linear segments is from 100 to 500 nm, the diameter is about 80 nm; the angle between segments varies from 30 to 90°. The total nanochain lengh reaches 100 microns. The mechanism of silver nanochain formation is discussed. 10.18720/MPM.3222017_12 chain-like silver nanowires; silver nanowires; chemical synthesis of nanostructures; metal nanoparticles https://mpm.spbstu.ru/article/2017.55.12/ MPM232_12_sosnin.pdf

RAR RUS 207-212 Mordovia State University N.P. Ogareva Ivlev

Saransk, Russia

Mordovia State University N.P. Ogareva Sigachyov

Saransk, Russia

Mordovia State University N.P. Ogareva Fomin

Saransk, Russia

Mordovia State University N.P. Ogareva Yudin

Saransk, Russia

Relaxation in resins with low-frequency mechanical cycling Hardened polyester and epoxy resins were tested for the relaxation of mechanical stresses, depending on the initial stress (2.6 ÷ 24MPa), time and temperature (15 ÷ 45 °C). The dependence of stress on time in the relaxation of resins in the investigated ranges of mechanical stresses is described by the logarithmic function characteristic for stress relaxation in crystalline solids (metals) 10.18720/MPM.3222017_13 epoxy resin; polyester resin; relaxation; mechanical stress https://mpm.spbstu.ru/article/2017.55.13/ MPM232_13_ivlev.pdf

RAR RUS 213-221 Peter the Great St. Petersburg Polytechnic University Lapin

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Kuzkin

St.Petersburg, Russia

On calculation of effective elastic properties of materials with cracks A simple approach for calculation of anisotropic effective elastic properties of cracked materials is presented. Square computational domain containing randomly distributed cracks under plane strain conditions is considered. Effective elastic properties are expressed in terms of average displacement discontinuities on cracks in three test problems: uniaxial loading in two orthogonal directions and pure shear. These problems are solved using the displacement discontinuity method. Resulting effective compliances are averaged over realizations with different crack distributions. This approach is employed for calculation of effective elastic properties for two particular crack configurations: (i) one family of parallel cracks and (ii) two families of parallel cracks inclined at angle 30°. Crack densities up to 0.8 are considered. It is shown that for both configurations the effective elastic properties are orthotropic even at large crack densities. Dependencies of Young's moduli on crack density are obtained. At crack densities up to 0.1, the effective properties can be estimated analytically using the noninteraction approximation (NIA). At higher crack densities, the NIA strongly overestimates effective stiffnesses. Quantitative agreement with results obtained in the literature using more sophisticated methods is demonstrated. 10.18720/MPM.3222017_14 effective elastic properties; cracked materials; crack interactions; orthotropy; noninteraction approximation; boundary element method; displacement discontinuity method https://mpm.spbstu.ru/article/2017.55.14/ MPM232_14_lapin.pdf

RAR RUS 222-236 École Polytechnique de Montréal Baharnezhad

Canada

KN Toosi University of Technology Golhin

Iran

In-situ measurement and finite element simulation of thermo-mechanical properties of AA 6063 aluminum alloy for MIG weldment The metal inert gas (MIG) welding and the crucial parameters influenced on the thermal and mechanical behaviours, and microstructure of AA 6063 aluminum were investigated through the experiment and the FE simulation. A thermo-mechanical model was extended using the finite element software of ABAQUS. In this manner, the thermal distribution and time-temperature histories made during MIG welding were derived. To achieve more accuracy, a subroutine was developed by FORTRAN. The real-time temperature measurements and the effective parameters of the thermal distribution, including the welding speed and the arc voltage were studied by conducting MIG bead-on-plate welds and the residual stresses derived from the simulation were compared with the empirical observations. The results depicted that the simulation would estimate rigorously the temperature gradients and the fields of welding-induced stress. The microstructural and microhardness examinations were also conducted which allowed - alongside the TTT curve - the phases precipitated and the heat sink effects were studied and foreseen. Indeed, the microstructure images demonstrated that the overaged, agglomerated β-Mg2Si phases, in the HAZ, and the modified β-AlFeSi pseudo-platelike precipitates alongside the smaller and coarsened β-Mg2Si phases, in the fusion zone, were precipitated. 10.18720/MPM.3222017_15 FE simulation in-situ measurement 6063 aluminum welding residual stress thermo-mechanical properties TTT curve microstructural examination https://mpm.spbstu.ru/article/2017.55.15/ MPM232_15_baharnezhad.pdf