Materials physics and mechanics

RAR RUS 1-12 0000-0002-6259-2019 St. Petersburg Institute of Technology (Technical University) Erofeev D.A.

St. Petersburg, Russia

0000-0001-8358-7211 St. Petersburg Institute of Technology (Technical University) Pirozhnikov P.B.

St. Petersburg, Russia

0000-0001-7536-2258 Peter the Great St. Petersburg Polytechnic University Keresten I.A.

St. Petersburg, Russia

0000-0003-4698-1484 Institute of Medical Education of Almazov National Medical Research Centre Titov A.G.

St. Petersburg, Russia

Experimental determination of physical, chemical and surface properties of biocompatible thermoplastic The main purpose of this research is determination of physical, chemical and surface properties of thermoplastics, which were certificated for medical employment, for implant or prosthesis manufacturing. The physical and chemical structure of thermoplastics (polyacrylonitrile-co-butadiene-co-styrene, polycarbonate, polyetherimide) were investigated with the Fourier-transform infrared spectroscopy (FTIR), differential thermal and thermogravimetric analysis (DTA/TG), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (XRD) and scanning electron microscopy (SEM). The surface of all investigated thermoplastics had a transition or a hydrophobic state. The contact angle hysteresis by distilled water was in range 95.6–103.0° that indicates sticky wetting behavior of surfaces. The contact angle by blood plasma was in the range 84.7–92.1°, depending on the chemical structure of the thermoplastic polymer. Despite the lower contact angle value of the blood plasma, the amount of its adsorption was greater than in case of distilled water, and it should be considered in development of medical polymer devices. 10.18149/MPM.5232024_1 thermoplastics polyacrylonitrile-co-butadiene-co-styrene polycarbonate polyetherimide endoprosthetics physical and chemical properties surface wetting https://mpm.spbstu.ru/article/2024.102.1/ 1-Erofeev-et-al.pdf

RAR RUS 13-21 Moscow State University of Civil Engineering Razakova

Moscow, Russia

N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences Turusov

Moscow, Russia

Influence of adhesive interaction on the sound speed in layered composites There are the adhesive interaction parameters influence between soft polymer and steel layers to the velocity of the longitudinal sound wave in this paper. Numerical and experimental tests of the sound speed in two composite and one polymer samples are considered. The mixture formula was used to determine the elastic parameters in numerical calculations with contact layer. The model, which included the contact layer, allows calculating the layered composites elastic modulus with certain geometric and mechanical parameters of adhesive interaction. Authors have compared the results of numerical calculations and physical experiment. It was found that the adhesive interaction parameters in the calculation of layered structures is necessary to consider because the adhesive connecting polymer layers with the steel layers have experience comprehensive stretching which affects to the elastic and acoustic parameters of the samples. 10.18149/MPM.5232024_2 layered materials contact layer Young's modulus Poisson ratio adhesion contact tunable materials material properties polymer https://mpm.spbstu.ru/article/2024.102.2/ 2-Razakova.pdf

RAR RUS 22-32 Peter the Great St. Petersburg Polytechnic University Novokshenov

St.Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Vershinin

St. Petersburg, Russia

Peter the Great St. Petersburg Polytechnic University Abdulin

St. Petersburg, Russia

Topology optimization algorithm for heterogeneous anisotropic materials and structures A two-phase topology optimization method is proposed, determines not only the ratio of the phases of high and low stiffness at each point of the body, but also the angle of rotation of the axes of anisotropy. The proposed method makes it possible to significantly improve the functionality of the products being developed. The topology optimization of the two-phase material is implemented using the method of moving asymptotes, and the angle of rotation of the anisotropy axes is aligned along the main axes of the stress tensor. As an example, a rectangular elastic plate is considered, with joint constraints in the two lower corners and the force in the middle of the upper face. The problem of simultaneous optimization of phases and axes of anisotropy is solved for this plate. The obtained results are analyzed, after which the correctness of the developed algorithm is concluded. 10.18149/MPM.5232024_3 topology optimization method of moving asymptotes solid isotropic material with penalization orthotropic materials multi-material https://mpm.spbstu.ru/article/2024.102.3/ 3-Novokshenov-et-al.pdf

RAR RUS 33-43 Volgograd State Agrarian University Yushkin

Volgograd, Russia

Volgograd State Agrarian University Kiseleva

Volgograd, Russia

Financial University under the Government of the Russian Federation Kirsanova

Moscow, Russia

0000-0002-7098-5998 FGBOU VPO Volgograd State Agrarian University Nikolaev

Volgograd, Russia

0000-0002-1027-1811 FGBOU VPO Volgograd State Agrarian University Klochkov

Volgograd, Russia

Variants of physical equations in a curvilinear coordinate system and their comparison based on mixed FEM In arbitrary curvilinear coordinate system under elastoplastic deformation, a comparative analysis of three variants of the constitutive equations at the loading step was performed. In the first variant, the equations of the theory of plastic flow were used, according to which the strain increment had been divided into elastic and plastic parts. The cumbersomeness of the algorithm for obtaining expressions for the components of the plastic strain increments tensor in an arbitrary curvilinear coordinate system is shown, which leads to the lack of the possibility of obtaining the matrix dependence of physical equations at the loading step. In the second variant, to obtain plastic strain increments, the hypothesis of their proportional dependence on the components of the stress increments deviator was used. The constitutive equations were also obtained by summation of the elastic strains increment and plastic strains increment. In the third variant, the hypothesis of the division of strain increments into elastic and plastic parts was not used. The physical equations were written using the assumption that there was a proportional dependence between the components of the strain increment deviators and stress increment deviators. Using the example of calculating the shell of revolution, the preference of the third variant of the constitutive equations for elastoplastic deformation is shown. 10.18149/MPM.5232024_4 shell of revolution physical nonlinearity hexahedral finite element mixed functional mixed FEM implementation https://mpm.spbstu.ru/article/2024.102.4/ 4-Kiseleva_et-al.pdf

RAR RUS 44-57 SEA College of Engineering and Technology Manjunath

Karnataka, India

Brindavan College of Engineering Kaviti

Karnataka, India

0000-0001-6549-6340 Siddaganga Institute of Technology Tumkur Auradi

Tumkur, India

Sri Sai Ram College of Engineering Chandrasekhar

Karnataka, India

JNN College of Engineering Vijayakumar

Karnataka, India

0000-0002-8248-7603 Aircraft Research and Design Centre, Hindustan Aeronautics Limited Nagaral Madeva

Bangalore, India

New Horizon College of Engineering Rajesh

Karnataka, India

Synthesis and tensile behavior of Al7475-nano B4C particles reinforced composites at elevated temperatures Materials with superior mechanical and wear properties, high strength, high stiffness, and low weight are necessary for modern technology. Mechanical characteristics of metal matrix composites are crucial to their potential use as structural materials. The current research focuses on the preparation of Al7475 alloy with 400 to 500 nm sized B4C a composite using a liquid metallurgy technique. Al7475 alloy was used to make composites with 2, 4, 6, 8 and 10 wt. % of B4C particles. Microstructural analysis was performed on the produced composites using SEM and EDS. Density, hardness, ultimate strength, yield strength, and elongation as a percentage were all measured as per ASTM norms. Further, tensile tests were conducted at room temperature, 50 and 100 °C elevated temperatures. SEM images showed that the boron carbide particles were evenly dispersed throughout the Al7475 alloy. EDS spectrums verified that Al7475 alloy contains boron carbide particles. By incorporating dual particles into the matrix, the density of Al alloy composites was lowered. Al7475 alloy with B4C composites exhibited superior tensile properties at room and elevated temperatures as compared to the base alloy. 10.18149/MPM.5232024_5 Al7475 alloy B4C particles microstructure density tensile behavior https://mpm.spbstu.ru/article/2024.102.5/ 5-Chandrasekhar_et-al.pdf

RAR RUS 58-72 57200791697 0009-0007-1272-3993 Siberian Federal University Motkov

Krasnoyarsk, Russia

57192191063 0009-0004-0288-1814 Siberian Federal University Timofeev

Krasnoyarsk, Russia

Ufa State Aviation Technical University Enikeev

Ufa, Russia

Ufa State Aviation Technical University Murashkin Maxim Yu.

Ufa, Russia

Ufa University of Science and Technology Medvedev Andrey E.

Ufa, Russia

Ufa University of Science and Technology Zhukova Olga O.

Ufa, Russia

Ufa University of Science and Technology Kazykhanov

Ufa, Russia

Ufa University of Science and Technology Shaikhulova Aygul F.

Ufa, Russia

Unique properties of the Al-0.5Fe-0.3Cu alloy, obtained by casting into an electromagnetic crystallizer, after equal-channel angular pressing and cold drawing The effect of equal-channel angular pressing (ECAP) and subsequent cold drawing (CD) on the microstructure and properties of the Al-0.5Fe-0.3Cu (wt. %) alloy produced by electromagnetic casting (EMC) is examined. The high rate of crystallization of the alloy ensured the formation of a solid solution of copper in the aluminum matrix, while iron was completely bound in intermetallic particles of the Al-Fe and Al-Fe-Cu types. A distinctive feature of ECAP processing followed by CD is the presence of signs of both ECAP and CD in the structure of the processed alloy. Moreover, the syncretic effect of two deformation methods, implementing different deformation schemes, led to the appearance of features that were absent in the alloy structures after ECAP or after CD. Presence of the unique ultra-fine grained (UFG) microstructure, formed as a result of the combined ECAP+CD treatment, led to an increase in the tensile strength of wires made of the Al-0.5Fe-0.3Cu alloy to 342 MPa while maintaining a relatively high electrical conductivity of 55.5 % IACS. Compared to the commercial scale alloys, the wire (with a UFG structure) from the Al-0.5Fe-0.3Cu alloy demonstrates either equal (6000 series alloys) or improved (8000 series alloys) mechanical strength and electrical conductivity. Introduction of copper into Al-0.5Fe alloy, obtained using the EMC method, allows to even further improve the strength-conductivity combination of this alloy. 10.18149/MPM.5232024_6 aluminum alloy Al-Fe-Cu electromagnetic crystallization equal-channel angular pressing cold drawing UFG microstructure electrical conductivity strength thermal stability https://mpm.spbstu.ru/article/2024.102.6/ 6-Medvedev-et-al.pdf

RAR RUS 73-79 Ioffe Institute Orlova T.S.

St.Petersburg, Russia

Ioffe Institute Sadykov

St. Petersburg, Russia

Outstanding ductility of high-strength ultrafine-grained aluminium at cryogenic temperatures By decreasing the temperature of the tensile tests from 293 to 77 K, a drastic increase in ductility (elongation to failure ~ 40 % and uniform elongation ~ 25 %) was demonstrated for the first time, along with an increase in strength (yield stress ~ 235 MPa and ultimate tensile strength ~ 265 MPa) for ultrafine-grained aluminium structured by combination of equal-channel angular pressing and cold rolling with subsequent annealing. The increase in ductility at 77 K is accompanied by an increase in the strain hardening coefficient. The physical reasons for the significant increase in ductility at 77 K are discussed in comparison with the peculiarities of microstructure. The obtained combination of ductility and strength opens up prospects for the use of this material at cryogenic temperatures, as well as the application of cryogenic temperatures for the formation of its products of complex shapes. 10.18149/MPM.5232024_7 aluminium ultrafine-grained structure ductility strength cryogenic temperatures https://mpm.spbstu.ru/article/2024.102.7/ 7-Orlova.pdf

RAR RUS 80-85 F-1445-2014 7202768874 0000-0003-3738-408X ITMO University Romanov Alexey alexey.romanov@niuitmo.ru

St.Petersburg, Russia

ITMO University Spiridonov Vladislav

St.Petersburg, Russia

ITMO University Panov Dmitrii

St.Petersburg, Russia

Yanka Kupala Grodno State University Ivanov

Grodno, Belarus

ITMO University Bauman Dmitrii

St.Petersburg, Russia

The effect of high-temperature annealing on the properties of bulk β-Ga2O3 obtained in different growth atmospheres The work presents the results of the experiments on annealing in air of bulk crystals of gallium oxide grown in Ar+O2 and CO2 atmospheres at a temperature of 1400 °C. The annealing time was 5 hours; the time to reach the temperature was 3.5 hours; the cooling time was 20 hours. Annealed samples show increasing of transmission in infrared area of electromagnetic spectrum and decreasing of width of X-ray rocking curve which means the reduction of the number of defects in crystals. Full width at half maximum of rocking curve for annealed samples was almost the same for both atmospheres: FWHMa = 84 arcsec for sample grown in Ar+O2 atmosphere and FWHMa = 80 arcsec for sample grown in CO2, which means that after annealing, the quality of the samples became comparable, despite the initial difference. 10.18149/MPM.5232024_8 β-Ga2O3 bulk crystal annealing optical spectroscopy XRD https://mpm.spbstu.ru/article/2024.102.8/ 8-Spiridonov_et-al.pdf

RAR RUS 86-95 Polzunov Altai State Technical University Bebikhov Yuriy V.

Barnaul, Russia

Polzunov Altai State Technical University Semenov Alexander S.

Barnaul, Russia

Altai State Technical University Poletaev Gennady M.

Barnaul, Russia

Polzunov Altai State Technical University Gafner

Barnaul, Russia

Polzunov Altai State Technical University Gafner

Barnaul, Russia

Siberian State Industrial University Zorya

Novokuznetsk, Russia

Influence of aluminum shell on the process of devitrification of amorphous titanium nanoparticles: molecular dynamics simulation A study of the amorphous nanoparticle devitrification process of titanium during heating at a rate of 5∙1011 K/s in vacuum conditions and with the presence of aluminum shell was conducted using molecular dynamics modeling. It was shown that the presence of an aluminum shell leads to a significant increase in the nanoparticle devitrification temperature of titanium. For the considered particle sizes (with diameter from 1.75 to 11 nm) the difference was approximately 200 K. In addition, it was discovered that in vacuum conditions, crystalline embryos are primarily formed near the surface of the particle, while in the presence of an aluminum shell, they are formed, on the contrary, first in the volume of the particle. Thus, according to the results of molecular dynamics modeling, a decrease in the size of titanium particles and the presence of an aluminum shell increase the temperature range for the existence of the amorphous phase of titanium. 10.18149/MPM.5232024_9 molecular dynamics nanoparticle devitrification crystallization amorphous metal https://mpm.spbstu.ru/article/2024.102.9/ 9-Poletaev-et-al.pdf

RAR RUS 96-107 M.S. Ramaiah University of Applied Sciences Badiger

Bengaluru, India

Jawaharlal Nehru National College of Engineering Ramakrishna

Shivamogga, India

Interaction of two circular holes in an infinite plate by body force method The body force method is used to perform stress analysis around two circular holes with equal and different sizes in an infinite plate subjected to uni-axial loading. The elasticity solution for a point force in an infinite plate is used as the fundamental solution. Traction free boundary conditions are satisfied at the midpoint of segments. Stress concentration factors obtained by body force method are compared with the results available in the literature. It is noted that accurate results are obtained with a small number of segments of the discontinuity. The body force method is simple, yet robust method useful in performing stress analysis of bodies with discontinuities. 10.18149/MPM.5232024_10 two unequal circular holes body force method stress concentration factor infinite plate uni-axial loading https://mpm.spbstu.ru/article/2024.102.10/ 10-Badiger%2C-Ramakrishna-.pdf

RAR RUS 108-120 St. Petersburg State University Selyutina

St.Petersburg, Russia

St. Petersburg State University Igusheva

St. Petersburg, Russia

St. Petersburg State University Petrov

St.Petersburg, Russia

The role of the hydrostatic pressure under dynamic fracture of rocks Within the context of the structural-temporal approach, the dynamic effects of the strength characteristics of rocks arising due to hydrostatic pressure are analysed. The key idea of the proposed approach is the introduction of the incubation time parameter for describing material fracture processes, which is interpreted as the main measure of material response. Theoretical velocity dependencies of the fracture toughness for marble and granite, subjected to different values of external hydrostatic pressure, as well as for dry and wet sandstones, are predicted based on the proposed approach. The calculated incubation times for marble and granite are allowed to establish a linear function between incubation time and hydrostatic pressure. The obtained values of incubation times are compared according to the velocity dependencies of the fracture toughness and the velocity dependencies of the strength of rocks differing in external hydrostatic pressure or moisture level. It is shown that the incubation time depending on the external hydrostatic pressure or on the moisture of rocks is similarly changed. 10.18149/MPM.5232024_11 dynamic fracture toughness hydrostatic pressure structural-temporal approach fracture incubation time loading rate https://mpm.spbstu.ru/article/2024.102.11/ 11-Selyutina_et-al.pdf

RAR RUS 121-144 Chandigarh Group of Colleges Juneja

Jhanjeri, Punjab, India

National Institute of Technology Bhardwaj

Hamirpur, Himachal Pradesh, India

Chandigarh University Sharma

Punjab, India

National Institute of Technology Sharma

Hamirpur, Himachal Pradesh, India

Laboratory study on use of lime and waste materials in improving geotechnical properties of clay 10.18149/MPM.5232024_12 clay fly ash construction demolition waste lime plastic waste https://mpm.spbstu.ru/article/2024.102.12/ 12-Juneja-Gaurav-_et-al.pdf

RAR RUS 145-153 Institute for Problems in Mechanical Engineering of the Russian Academy of Sciences Polyanskiy

St. Petersburg, Russia

Institute for Problems in Mechanical Engineering of the Russian Academy of Science Varshavchik

St. Petersburg, Russia

St.-Petersburg State University Chevrychkina

St.Petersburg, Russia

Research of hydrogen diffusion in a material with various types of traps A model of the process of hydrogen diffusion over the crystal structure in solids is presented. A defect-free and defective structure are considered. This study is relevant for the process of hydrogen embrittlement, which can lead to premature destruction of the material. A hypothesis about the creation of a surface layer upon pre-charging a sample with hydrogen is considered, which is necessary for further study of the hydrogen desorption process. The effect of the surface layer on the extraction curves is studied, and the simulated extraction curves are compared with the experimental ones. The results obtained make it possible to better understand the interaction of hydrogen atoms with the structure of a solid. 10.18149/MPM.5232024_13 hydrogen diffusion hydrogen charging hydrogen traps hydrogen desorption diffusion equation https://mpm.spbstu.ru/article/2024.102.13/ 13-V_A_-Polyanskiy%2C-E_A_-Varshavchik-A_A_-Chevrychkina-.pdf

RAR RUS 154-160 South Ural State University Shaburova

Chelyabinsk, Russia

Chromium plating of steel parts using the thermoemission field Experimentally, it was found that if a second metal component is added to the technological backfill during thermal diffusion chromium plating or if the inert separating additive of corundum is replaced by minerals-solid electrolytes, a current appears in the technological backfill directed to the saturable part. The appearance of an electric field is due to the emission of electrons (metal components of the filling) and oxygen anions (solid oxide electrolytes). It is determined that the emission flux makes a contribution to the saturation process that is commensurate with the diffusion flux formed according to Fick's laws. Experiments show an acceleration of diffusion processes and an increase in the depth of the diffusion layer of chromium by 2–2.5 times. 10.18149/MPM.5232024_14 thermal diffusion chromium plating thermal emission field diffusion depth https://mpm.spbstu.ru/article/2024.102.14/ 14-Shaburova.pdf