Materials physics and mechanics

RAR RUS 1-7 ITMO Univesity V.G. Dubrovskii

St.Petersburg, Russia

ITMO University Sokolova

St.Petersburg, Russia

ITMO University Rylkova

St.Petersburg, Russia

ITMO University Zhiglinsky

St.Petersburg, Russia

Composition and contact angle of Au-III-V droplets on top of Au-catalyzed III-V nanowires We present a model which allows for the self-consistent determination of the stationary group III and V concentrations in the droplet and the contact angle versus the group III and V fluxes during the Au-catalyzed vapor-liquid-solid growth of III-V nanowires. The nanowire axial growth rate in the mononuclear regime is taken in the Zeldovich form. Chemical potentials of the group III and V atoms in liquid are considered within the regular solution model. We show how the group III content and the droplet contact angle can be increased be either decreasing group V flux or increasing group III flux. The group V concentration usually decreases for higher contact angles. Overall, these results can be used for modeling and fine tuning of the droplet shapes and compositions influencing the morphology and the preferred crystal structure of Au-catalyzed III-V nanowires in different epitaxy techniques. 10.18720/MPM.3612018_1 III-V nanowires; droplet composition; contact angle; VLS growth https://mpm.spbstu.ru/article/2018.60.1/ MPM136_01_dubrovskii.pdf

RAR RUS 8-17 Universiti Malaysia Hassan

Terengganu, Malaysia

Universiti Malaysia Noruddin

Terengganu, Malaysia

The effect of lithium perchlorate on poly (sodium 4-styrenesulfonate): studies based on morphology, structural and electrical conductivity Solid polymer electrolytes (SPEs) of Poly(sodium 4-styrenesulfonate) (PSS) as a polymer host and lithium perchlorate (LC) as an ionic dopant were prepared using a single-solvent via solution casting technique. According to XRD analyses, the solid polymer electrolyte films were in amorphous phase and the coexistence of peaks of the materials (PSSand LC) confirmed that the complex films were successfully obtained. The SEM observations revealed that the films appeared to be rough, flat, and irregular shape of surfaces. The highest ionic conductivity (σ) of 7.21×10-6 S cm-1 was achieved at room temperature (303K) for the sample containing 15 wt.% LC. Solid polymer electrolytes (SPEs) of Poly(sodium 4-styrenesulfonate) (PSS) as a polymer host and lithium perchlorate (LC) as an ionic dopant were prepared using a single-solvent via solution casting technique. According to XRD analyses, the solid polymer electrolyte films were in amorphous phase and the coexistence of peaks of the materials (PSSand LC) confirmed that the complex films were successfully obtained. The SEM observations revealed that the films appeared to be rough, flat, and irregular shape of surfaces. The highest ionic conductivity (σ) of 7.21×10-6 S cm-1 was achieved at room temperature (303K) for the sample containing 15 wt.% LC. 10.18720/MPM.3522018_2 solid polymer electrolyte; poly(sodium 4-styrenesulfonate); lithium perchlorate; ionic conductivity; impedance spectroscopy https://mpm.spbstu.ru/article/2018.60.2/ MPM136_02_hassan.pdf

RAR RUS 18-38 The University of Tokyo Kawabata

Tokyo, Japan

The University of Tokyo Nakanishi

Tokyo, Japan

Nippon Steel and Sumitmo Metal Corporation Namegawa

Chiba, Japan

The University of Tokyo Aihara

Tokyo, Japan

Dissipation energy during brittle crack propagation in a single crystal of 3%Si-Fe alloy Brittle fracture in carbon steel seriously impacts structural safety. It is considered that the elementary step of the brittle fracture of polycrystalline steel corresponds to cleavage in each crystal grain and their connection process. However, the detailed mechanisms of brittle fracture are not completely understood. In this study, the elementary process of brittle crack propagation is clarified using the dynamic strain recording of a strain gauge near the crack path.The results indicate that the brittle crack propagation rate in a single crystal grain is much slower than the Rayleigh wave rate. To estimate the dissipation energy during crack propagation in a single crystal grain, dynamic finite element analyses were conducted by assuming constant critical stress during crack propagation. The dissipated energy is not small even inside a single crystal grain and appears to exhibit a proportional relationship with the stress intensity factor. 10.18720/MPM.3612018_3 brittle crack; steel; dissipation energy; single crystal https://mpm.spbstu.ru/article/2018.60.3/ MPM136_03_kawabata.pdf

RAR RUS 39-52 Berdyansk State Pedagogical University Kidalov

Berdyansk, Ukraine

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 of Problems of Mechanical Engineering RAS Osipov A.V.

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering of Russian Academy of Sciences Redkov

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS Grashchenko

St.Petersburg, Russia

Saint Petersburg National Research Academic University Soshnikov

St.Petersburg, Russia

Ioffe Institute Boiko

St.Petersburg, Russia

Ioffe Institute Sharkov

St.Petersburg, Russia

Berdyansk State Pedagogical University Dyadenchuk

Berdyansk, Ukraine

Growth of SiC films by the method of substitution of atoms on porous Si (100) and (111) substrates The mechanisms of growth of silicon carbide (SiC) films by the method of substitution of atoms on macro- and mesoporous silicon substrates (Si) of p- and n-type conduction are investigated. Significant dependence of the rate and the mechanism of nucleation of SiC layers on Si on the type of Si doping and its crystallographic orientation is experimentally found. Comparison of the experimental data with the theoretical results obtained earlier is performed. It is shown that the presence of the system of pores on the surface allows one to significantly increase the thickness of silicon transformed into SiC during the process of synthesis by the method of substitution of atoms, which was equal to 115 microns in our experiments. The obtained samples are studied by methods of scanning electron microscopy, micro-Raman spectroscopy, and X-ray diffraction analysis. Numerical simulation of the distribution of elastic stresses caused by the difference in thermal expansion coefficients (TEC) in the heterostructures of GaN/SiC/porous Si/Si is conducted. It is revealed that the presence of pores in the near-surface layers of Si leads to considerable relaxation of elastic stresses in GaN films caused by differences in the TEC between GaN and Si. 10.18720/MPM.3612018_4 silicon carbide; epitaxial films SiC on Si; epitaxy; gallium nitride films; aluminum nitride films; thin films growth; porous silicon substrate https://mpm.spbstu.ru/article/2018.60.4/ MPM136_04_kukushkin.pdf

RAR RUS 53-59 Nosov Magnitogorsk State Technical University Polyakova

Magnitogorsk, Russia

University of Padova Calliari

Padova, Italy

Nosov Magnitogorsk State Technical University Pivovarova

Magnitogorsk, Russia

Nosov Magnitogorsk State Technical University Gulin

Magnitogorsk, Russia

Approach to obtaining medium carbon steel wire with a specified set of mechanical properties after combined deformational processing Progressive development of metal ware manufacturing is closely connected with implementation of technologies with integrated or combined operations. Continuous method of wire deformational processing by drawing with bending and twisting was developed. Medium carbon steel wire with 0.5 %C was used for the experiments. The results of simulation in Deform-3D showed that distributions of tensile and compression stresses at combined deformational processing are uniform along the deformation zone. Microscopic analysis of the processed wire indicated that after combined deformational processing a homogeneous structure is formed in the medium carbon steel wire. After tensile test, it was proved that combination of drawing with bending and twisting allows ones to achieve the different combination of strength and ductile properties of medium carbon steel wire with one diameter and carbon content. 10.18720/MPM.3612018_5 medium carbon steel wire; combined deformation; drawing; bending; twisting https://mpm.spbstu.ru/article/2018.60.5/ MPM136_05_polyakova.pdf

RAR RUS 60-66 Nosov Magnitogorsk State Technical University Polyakova

Magnitogorsk, Russia

Nosov Magnitogorsk State Technical University Chukin

Magnitogorsk, Russia

University of Padova Brunelli

Padova, Italy

Nosov Magnitogorsk State Technical University Efimova

Magnitogorsk, Russia

Nosov Magnitogorsk State Technical University Golubchik

Magnitogorsk, Russia

Study of texture and microstructure formation in medium carbon steel wire submitted to combined deformation by drawing with bending and twisting Deformation scheme plays the significant role in texture and microstructure formation of the processed metal ensuring the definite level mechanical properties. Medium carbon steel wire with 0.5 %C was chosen for investigation. It was deformed by combined deformational processing by drawing with bending and twisting. XRD analysis of the processed wire showed that after drawing fiber texture is formed along the drawing direction. Combined deformational processing by drawing with bending and drawing with bending and twisting results in texture formation in the wire in each case in transverse direction. In microstructure of medium carbon steel wire deformation and breakdown of cementite lamellae can be noticed after all kinds of deformational processing. 10.18720/MPM.3612018_6 medium carbon steel wire;combined deformation; texture; microstructure https://mpm.spbstu.ru/article/2018.60.6/ MPM136_06_polyakova.pdf

RAR RUS 67-75 7006355365 0000-0002-6663-6357 Kuban State University Babeshko Vladimir

Krasnodar, Russia

57201387701 Southern Scientific Center RAS Evdokimova Olga

Rostov-on-Don, Russia

6602333282 0000-0003-1283-3870 Kuban State University Babeshko Olga

Krasnodar, Russia

Kuban State University Zaretskaia

Krasnodar, Russia

Kuban State University Gorshkova

Krasnodar, Russia

Kuban State University Mukhin

Krasnodar, Russia

Kuban State University Gladskoi

Krasnodar, Russia

On the behavior of materials with defective coating under different contact conditions On a multi-layered base described by the Lamé equations there is a defective coating in the form of Kirchhoff plates. Defects of two types divide the covering into two half-planes with parallel ends, which, in the first case, are spaced apart from each other by a finite distance, and in the second case the distance is absent. All types of contact of coatings with a base are studied: in the absence of friction, in the presence of shearing stresses, with complete cohesion of the coatings and the base. The stress concentration in the end zone is investigated. The block-element method is used, which allows for studying the boundary problems mathematically. A complete analysis of the stress concentration features in the problem is performed. 10.18720/MPM.3612018_7 block element; factorization; topology; integral and differential factorization methods; exterior forms; block structures; boundary problems; bodies with coverings; hidden defects https://mpm.spbstu.ru/article/2018.60.7/ MPM136_07_babeshko.pdf

RAR RUS 76-84 Kabardino-Balkar State University. named H. M. Berbekov Borukaev

Nalchik, Russia

Kabardino-Balkar State University. named H. M. Berbekov Gaev

Nalchik, Russia

Kabardino-Balkar State University. named H. M. Berbekov Shetov

Nalchik, Russia

Kabardino-Balkar State University. named H. M. Berbekov Shaov

Nalchik, Russia

Peter the Great St. Petersburg Polytechnic University Orlov

St.Petersburg, Russia

Electroducing polymer composites based on high density polyethylene and technical-carbon Electrically conductive polymer composites based on high-density polyethylene and carbon black are obtained. It is shown that polymer composites possess a positive temperature coefficient of electrical resistance. The amount of carbon black required to form electrically conductive paths in a polymer matrix is determined. Dependence of physico-mechanical and rheological characteristics of composites on the content of carbon black is revealed. The concentration interval of carbon black is determined, in which the optimal combination of physico-mechanical, rheological and electrophysical properties of composites. 10.18720/MPM.3612018_8 polyethylene; carbon black; composites; properties; electrical; mechanical; rheological; morphology https://mpm.spbstu.ru/article/2018.60.8/ MPM136_08_borukaev.pdf

RAR RUS 85-91 Altai State Technical University Poletaev Gennady M.

Barnaul, Russia

Altai State Technical University Novoselova

Barnaul, Russia

Siberian State Industrial University Kovalenko

Novokuznetsk, Russia

Financial University under the Government of the Russian Federation, Barnaul brunch Kokhanenko

Barnaul, Russia

Financial University under the Government of the Russian Federation, Barnaul brunch Iliina

Barnaul, Russia

Molecular dynamics investigation of grain boundaries tensions in triple junctions in nickel In the work, the mutual tension of tilt grain boundaries with disorientation axes and in a triple junction on the example of nickel is investigated by the molecular dynamics method. The ratio of the boundary tensions found in the molecular dynamics model is compared with the ratio calculated using the Yang relation through the ratio of grain boundary energies. It is shown that both methods give close values. In addition, it was found that the elongation or contraction of low-angle tilt boundary at the triple junction motion is accompanied by the formation of zigzag displacements of atoms, which apparently appear due to the splitting and sliding of grain-boundary dislocations. The formation of new geometrically necessary dislocation during the boundary elongation occurred, as a rule, in the triple junction or in an already existing grain-boundary dislocation. 10.18720/MPM.3612018_9 molecular dynamics; triple junction; grain boundary; boundary migration; triple junction migration; boundary energy; boundary tension; tilt boundary https://mpm.spbstu.ru/article/2018.60.9/ MPM136_09_poletaev.pdf

RAR RUS 92-99 Peter the Great St. Petersburg Polytechnic University Mishin

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Shishov

St.Petersburg, Russia

Spectron Ltd. Kiselev

St.Petersburg, Russia

Spectron Ltd. Matsinkevich

St.Petersburg, Russia

Spectron Ltd. Rudnev

St.Petersburg, Russia

Spectron Ltd. Bukin

St.Petersburg, Russia

Investigation of the possibility of improving the X-ray fluorescence spectrometer analytical characteristics due to using the superfine beryllium foils Studies were made the possibilities of increasing the wave-dispersive X-rayfluorescence spectrometer analytical characteristics due to using the superfine beryllium foils5-8 μm thick in the X-ray detector. Investigations by the example of spectrometerSPECTROSCAN MAX-GVM showed that the decrease of foil thickness can significantlyincrease the spectrometer analytical characteristics in the determination of light elements(sodium and magnesium). It has been established what count rate increases 8.5 times for sodium and 4.6 times for magnesium due to using the X-ray windows with thickness of 5 and8 μm. Reducing of X-ray window thickness can be achieved by using beryllium foils obtained by severe cold plastic deformation. Such foils have increased plasticity, which allowsreducing the X-ray window thickness without spectrometer reliability decreasing. 10.18720/MPM.3612018_10 x-ray spectroscopy analysis; spectrometer; x-ray detector; thin beryllium foils; x-rays transmission https://mpm.spbstu.ru/article/2018.60.10/ MPM136_10_mishin.pdf

RAR RUS 100-113 Peter the Great St. Petersburg Polytechnic University Mishin

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Shishov

St.Petersburg, Russia

Investigation of the process of deformation and destruction of thin beryllium foils under static loading by external pressure In this paper numerical and experimental studies of deformation and fracture of thin beryllium disks with a thickness of 5-100 μm are performed. Disks, intended for use as X-ray windows, were obtained by the method of severe cold deformation. It is shown that beryllium foils under loading by external pressure (or bulge test) have higher values of ultimate strains than in tensile tests. It is established that the fracture at bulge test occurs at values of the accumulated plastic strain amounting to 15-20%, what very high for beryllium. 10.18720/MPM.3612018_11 thin beryllium foils; mechanical properties of beryllium foil; plasticity of beryllium; bulge test; beryllium fracture https://mpm.spbstu.ru/article/2018.60.11/ MPM136_11_mishin.pdf

RAR RUS 114-118 St. Petersburg State University Gorbushin

St.Petersburg, Russia

St. Petersburg State University Granichin

St.Petersburg, Russia

St. Petersburg State University Logachev

St.Petersburg, Russia

St. Petersburg State University Petrov

St.Petersburg, Russia

St. Petersburg State University Volkov

St.Petersburg, Russia

Destruction of the adhesion zone by combined pulsed - vibrational impacts The model of a string on an elastic foundation is applied to study adhesive zone delamination induced by combined vibrational - pulsed actions. The incubation time criterion is utilized in order to predict a critical delamination condition. The influence of the background ultrasonic field onto the value of threshold stress-pulse amplitudes is demonstrated using the example of several particular cases of external actions. A significant reduction of critical amplitudes is obtained with certain frequencies of background vibration field. 10.18720/MPM.3612018_12 adhesive zone; string on an elastic foundation; pulse-vibration effects https://mpm.spbstu.ru/article/2018.60.12/ MPM136_12_gorbushin.pdf

RAR RUS 121-130 Institute of Problems of Mechanical Engineering RAS Meshcheryakov Yu.I.

St.Petersburg, Russia

IPME RAS Atroshenko

St.Petersburg, Russia

On the mesoscopic mechanisms of spall fracture Four kinds of complex alloyed steel have been tested under uniaxial strain conditions within strain rate range of 215÷550 m/s. The kinematics of straining was studied by using SEM and optical microscopy of post-shocked specimens. The cross-section of targets is found to contain the mesoscopic rotational structures of complex configuration. Besides the free surface velocity, interference technique used allows the mean particle velocity profile and velocity variance to be registered in every shock loading. The spall strength is theoretically and experimentally found to be maximum at the strain rate where velocity variance equals to velocity defect. This condition means that local strain rate at the mesoscale equal to macroscopic strain rate. T hat strain rate corresponds to maximum density of rotations at the mesoscale. 10.18720/MPM.3612018_13 shock loading; spallation; rotational structures; velocity variance; velocity defect https://mpm.spbstu.ru/article/2018.60.13/ MPM136_13_meshcheryakov.pdf

RAR RUS 131-136 Peter the Great St. Petersburg Polytechnic University Kitaeva D.A.

St.Petersburg, Russia

Kyrgyz-Russian Slavic University Rudaev

Bishkek, Kyrgyzstan

On Macrokinetics under Dynamic Superplasticity The experimental study of deformation behavior of group industrial aluminum alloys in the broad temperature and high-speed ranges led to creation of the mathematical model for the case of simple tensile and compression, establishing the relationship between stress, temperature and kinetic variables, and responding to analytically formulated conditions of transition to superplastic state. Within synergetic conceptions we will choose the potential function in the form of assembling catastrophe from conditions of qualitative identity of the experimental data. It is added by the kinetic equations for the control parameter and inner state parameters. The given ratios are acceptable for the description of concrete regularities of deformation when the function of material sensitivity to the structural transformations is expressed. Basic model use allow to research nonequilibrium system reaction to behavior of thermodynamic response functions – the specific heat and entropy – and to establish implementations features of the irreversible indistinct phase transitions observed in the conditions of dynamic superplasticity for aluminum alloys. 10.18720/MPM.3612018_14 aluminum alloys; specific heat; entropy; superplasticity https://mpm.spbstu.ru/article/2018.60.14/ MPM136_14_kitaeva.pdf

RAR RUS 137-141 Admiral Makarov State University of Maritime and Inland Shipping Goloskokov

St.Petersburg, Russia

St.Petersburg State University Matrosov

St.Petersburg, Russia

Approximate analytical approach in analyzing an orthotropic rectangular plate with a crack The stretching of a rectangular plate with a crack parallel to one of its edges under the action of a uniformly distributed load is considered. An approximate analytical solution in the form of trigonometric polynomials is constructed by the superposition method using two solutions obtained by the method of initial functions (MIF). The stress-strain state in the neighborhood of the crack sides and the crack tip for orthotropic plates is investigated. 10.18720/MPM.3612018_15 method of initial functions; superposition method; cracks; method of analytical decomposition; plane problem of elasticity theory https://mpm.spbstu.ru/article/2018.60.15/ MPM136_15_goloskokov.pdf

RAR RUS 142-146 St.Petersburg State University Matrosov

St.Petersburg, Russia

St. Petersburg State University Suratov

St.Petersburg, Russia

Stress-strain state in the corner points of a clamped plate under uniformly distributed normal load The bending of a rectangular clamped thin plate under the uniformly distributed transverse load is considered. The solution of the Sophie Germaine equation is constructed by the method of initial functions (MIF). On two opposite sides the boundary conditions are satisfied exactly. Then, on the two remaining ones, the boundary conditions are satisfied approximately by the collocation method. The results of calculations of the stress-strain state at the corner points of the plate are given. 10.18720/MPM.3612018_16 method of initial functions; bending of a plate clamped; corner points https://mpm.spbstu.ru/article/2018.60.16/ MPM136_16_matrosov.pdf

RAR RUS 147-153 National Research Lobachevsky State University of Nizhni Novgorod Volkov

Nizhny Novgorod, Russia

Volga State University of Water Transport Desyatnikova

Nizhny Novgorod, Russia

Lobachevsky State University of Nizhni Novgorod Igumnov

Nizhni Novgorod, Russia

Defining relations of mechanics of damaged media effected by fatigue and creep A possible version of a model describing degradation of initial strength properties of structural alloys affected by fatigue and creep is introduced, based on the modern viewpoint of mechanics of damaged media (MDM). Processes of viscoplastic deformation and damage accumulation in structural alloys are analyzed using numerical modeling. Specia attention is paid to the issues of modeling the processes of viscoplastic deformation and damage accumulation for complex deformation processes accompanied by the rotation of main stress and strain tensor areas.New qualitative and quantitative features of the failure process are noted, which are connected with stressed-strained state history, damage degree, stress relaxation and other factors. 10.18720/MPM.3612018_17 modeling; mechanics of damaged media; complex deformation; fatigue life; sustained strength; failure; service life https://mpm.spbstu.ru/article/2018.60.18/ MPM136_17_volkov.pdf