Materials physics and mechanics

RAR RUS 1-29 Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

113263 6701854079 0000-0001-9909-2950 Institute of Problems of Mechanical Engineering RAS Sheinerman Alexander

St.Petersburg, Russia

Elastic Fields of Nanoscopic Inclusions in Nanocomposites An overview of the analytical solutions for the elastic fields of nanoinclusions in composite solids is given. Special attention is paid to the case of nanocomposites. Besides, a description of the most popular analytical procedures for the calculations of the elastic fields of inclusions in nanocomposites is provided. These procedures include the Green function method, the method of surface dislocation loops, integration of the equations of equilibrium, and the method of infinitesimal inclusions. Also, the solutions for the elastic fields of nanoinclusions, derived within linear elasticity, are discussed and compared with those obtained using atomistic simulations. It is shown that the linear elasticity approach is valid down to extremely small dimensions of nanoinclusions. Nanocomposites Inclusions https://mpm.spbstu.ru/article/2010.15.1/ MPM_10_1-2_P01.pdf

RAR RUS 30-36 Institute of Problems of Mechanical Engineering RAS Bobylev S.V.

St.Petersburg, Russia

7005573911 St.Petersburg State University Morozov N.F.

St.Petersburg, Russia

Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

Accommodation of Intergrain Sliding through Grain Boundary Migration in Deformed Nanomaterials A new micromechanism for accommodation of intergrain sliding in nanocrystalline metals and ceramics is suggested and theoretically described. The micromechanism represents the stress-driven migration of grain boundaries. In the framework of the suggested approach, intergrain sliding and stress-driven migration of grain boundaries accommodate each other, in which both these processes are intensified, and their combined action enhances ductility of a nanocrystalline material. We calculated the conditions at which intergrain sliding and stress-driven migration of grain boundaries cooperatively occur in nanoscopic grains in the athermal regime. Sliding Grain Boundary Deformation https://mpm.spbstu.ru/article/2010.15.2/ MPM_10_1-2_P02.pdf

RAR RUS 37-46 Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

113263 6701854079 0000-0001-9909-2950 Institute of Problems of Mechanical Engineering RAS Sheinerman Alexander

St.Petersburg, Russia

Grain Boundary Sliding and Nanocrack Generation near Crack Tips in Nanocrystalline Metals and Ceramics A model is proposed which describes nanocrack generation and growth near the tips of blunt cracks in nanocrystalline metals and ceramics. Within the model, the stress concentration near the tips of large enough blunt cracks induces grain boundary sliding that leads to dislocation formation in triple junctions of grain boundaries. The stress field created by these dislocations and the applied load near crack tips initiates nanocrack generation and growth. It is shown that an increase in the curvature radius of blunt crack tips and a decrease in grain size promote nanocrack growth. These tendencies are in good agreement with experimental data concerning low values of fracture toughness and ductility of most nanocrystalline solids. nanocrystalline materials grain boundaries cracks strength https://mpm.spbstu.ru/article/2010.15.3/ MPM_10_1-2_P03.pdf

RAR RUS 47-55 Govt. Vishwanath Yadav Tamaskar Post Graduate Autonomous College P.C. Choubey

India

Govt. Vishwanath Yadav Tamaskar Post Graduate Autonomous College J. Kaur

India

Govt. Vishwanath Yadav Tamaskar Post Graduate Autonomous College N.S. Suryanarayana

India

Govt. Vishwanath Yadav Tamaskar Post Graduate Autonomous College V. Dubey

India

Govt. Vishwanath Yadav Tamaskar Post Graduate Autonomous College G. Das

India

Kinetic Parameter and TL Glow Curve of In Doped NaCl Crystals The present work reports the thermally stimulated luminescence displayed by sodium with different percentages of indium as impurity the doped NaCl: In crystal after exposure to UV light is studied. The thermal glow curves exhibited by NaCl: In shows interesting results. The dependence of dopant concentration on TL in NaCl: In crystal is investigated. The interaction of ionizing radiations with matter leads to various effects, some of which leave memory in the target material. This memory effect can be seen as the after effects of the irradiation. This paper describes the sequence of the physical events beginning with the incidence of an ionizing particle. Leading to trail of atomic and electronic displacements which stabiles in the form of so called defect centers. The kinetics of the thermoluminescence process has been explained phenomenological. The TL phenomenon has found many particle applications. The most outstanding of these are in dosimetry and in archaeology. The paper deals mainly with the physical processes involved in the TL emission and allude briefly to its involvement in applied areas. NaCl Crystals Kinetic Parameter TL Glow Curve https://mpm.spbstu.ru/article/2010.15.4/ MPM_10_1-2_P04.pdf

RAR RUS 56-61 Siliguri Institute of Technology Bhattacharya

India

Institute of Engineering and Management Bar

India

Jadavpur University Roy

India

Aveiro University Graca

Portugal

Aveiro University Valente

Portugal

Fractal Dimensionality of Ion Conduction in Glassnanocomposites We have reported the variation of dc conductivity with annealing time and the imaginary part of modulus spectra of Ag+ ions in the frequency range 40 Hz-110 MHz of the heat-treated sample 0.70AgI-0.15Ag2O-0.015Cu2O-0.135MoO3 at room temperature. We have observed that the variation of dc conductivity with annealing time shows a linear relationship, which indicates that ion conduction process is independent of the annealing time. We have also observed that the variation of relaxation time with annealing time follows a proposed power law from which the fractal dimensionality of the ion motion is predicted. The stretched exponent, obtained from the imaginary part of modulus spectra is found to vary with the annealing time which indicates the change in structure during annealing. Glassnanocomposites Fractal Dimensionality Ion Conduction https://mpm.spbstu.ru/article/2010.15.5/ MPM_10_1-2_P05.pdf

RAR RUS 62-71 Belgorod State University Ivanov

Belgorod, Russia

Belgorod State University Manokhin

Belgorod, Russia

Belgorod State University Kolobov

Belgorod, Russia

Belgorod State University Nechayenko

Belgorod, Russia

Phase Composition and Microstructure of Ti-6Al-4V Alloy after Hydrogen-Plastic Working The influence of combination of thermohydrogen treatment and plastic working of Ti-6Al-4V (VТ6 Ru) titanium alloy on its microstructure and phase composition has been investigated. The possibility to form and fix the ordered α2-phase (Ti3Al) with the help of reversible hydrogen alloying is demonstrated. Regularities of the influence of warm plastic deformation of hydrogen-charged alloy VТ6 on volume ratio of α2-phase and its morphology as well as on the tensile strength at elevated temperatures have been investigated. Ti-Al-V Alloys Phase Composition Microstructure Hydrogen-Plastic Working https://mpm.spbstu.ru/article/2010.15.6/ MPM_10_1-2_P06.pdf

RAR RUS 72-81 Holy Cross College Louis

Tamil Nadu, India

Holy Cross College Jayam

Tamil Nadu, India

St. Jerome's College Raj

Tamil Nadu, India

Band Structure, Density of States and Superconductivity of Adsorbed Titanium Chains on (8,8) and (14,0) Carbon Nanotubes The electronic band structure and density of states of (8,8) armchair and (14,0) zigzag single walled carbon nanotubes (SWCNT) are investigated using densityfunctional calculations. The band structure of the pure (14,0) zigzag nanotube indicates that it is a semiconductor where as the band structure of pure (8,8) armchair tube exhibits metallic behavior. When a titanium chain is adsorbed on the carbon nanotube, the (14,0) zigzag tube changes from semiconductor to metal and the (8,8) armchair tube transforms from metal to semiconductor. In both the cases there is a net transfer of charge from the metal chain atom to the carbon atom. The delocalized 3d electrons from the titanium chain generate additional states in the band gap regions of the semiconducting tubes transforming them into metals. The band structures of Ti adsorbed nanotubes are completely different from that of pure nanotubes. The band structure results are used to study the superconducting behaviour of pure (8,8) armchair nanotube and the Ti adsorbed (14,0) zigzag nanotube. The superconducting transition temperatures, Tc, for the pure (8,8) nanotube and the Ti adsorbed (14,0) nanotube are computed for different values of Debye temperature. The electron-phonon interaction and superconducting transition temperature are small in (8,8) armchair tube and considerable in Ti adsorbed (14,0) zigzag tube. Based on this, we hint at room temperature superconductivity in carbon nanotube. Titanium Chains Carbon Nanotubes Band Structure Density of States Superconductivity https://mpm.spbstu.ru/article/2010.15.7/ MPM_10_1-2_P07.pdf