Materials physics and mechanics

RAR RUS 108-148 0000-0003-0727-6352 Institute of Problems of Mechanical Engineering RAS Gutkin M. Yu.

St.Petersburg, Russia

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

St.Petersburg, Russia

Defect Structures at Interfaces in Nanocrystalline and Polycrystalline Films Theoretical models of interfaces and misfit defects in poly- and nanocrystalline films are considered. A general classification of interphase boundaries are given, and partly incoherent interfaces are described. The faceting of grain boundaries under misfit stress in thin films is discussed. It is shown that misfit strain can be accommodated by grain boundary dislocations and disclinations, in which case the dislocation and disclination mechanisms of accommodation can act simultaneously under certain conditions. Special attention is paid to the structure and properties of high-Tc superconductor films. We discuss a variety of grain boundary structures and their effect on high-Tc superconductivity. Structural transformations of the grain boundaries are also considered. It is demonstrated that the formation of nanograins with 90° tilt boundaries can be an alternative mechanism of misfit strain accommodation. polycrystalline films nanocrystalline films interfaces grain boundaries misfit defects dislocations disclinations high-Tc superconductors https://mpm.spbstu.ru/article/2009.11.1/ MPM_8_2_P01.pdf

RAR RUS 149-154 Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

7003559440 0000-0003-2192-0386 Institute for Problems of Mechanical Engineering RAS Skiba Nikolai nikolay.skiba@gmail.com

St. Petersburg, Russia

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

St.Petersburg, Russia

Misfit Stress Relaxation through Grain Boundary Diffusion in Nanocrystalline Films A model is suggested that describes a special micromechanism of misfit stress relaxation in nanocrystalline films, namely misfit stress relaxation through grain boundary diffusion. Within the model, the characteristic time of misfit stress relaxation is estimated for such metallic film/substrate systems as Ni/Cu and Cu/Ag. nanocrystalline materials diffusion films. https://mpm.spbstu.ru/article/2009.11.2/ MPM_8_2_P02-Rus.pdf

RAR RUS 155-164 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

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

St.Petersburg, Russia

Aristotle University of Thessaloniki Aifantis E.C.

Thessaloniki, Greece

Effect of Grain Boundary Migration on Fracture Toughness of Nanocrystalline Materials A model is suggested that describes the effect of grain boundary (GB) migration on crack propagation in deformed nanocrystalline materials. Within the model, GB migration occurs under the action of high shear stresses acting near crack tips and is accompanied by the formation of the quadrupoles of wedge disclinations. It is shown that GB migration hinders crack growth and thus increases the fracture toughness of deformed nanocrystalline materials. Nanocrystalline Materials Fracture Toughness Cracks Grain Boundary https://mpm.spbstu.ru/article/2009.11.3/ MPM_8_2_P03-Rus.pdf

RAR RUS 165-173 Kalasalingam University Thiruchitrambalam

Tamilnadu, India

Tamilnadu College of Engineering Alavudeen

India

A.C.College of Engg and Technology Athijayamani

India

Anna University Chennai Venkateshwaran

India

Anna University Chennai Perumal

India

Improving Mechanical Properties of Banana/Kenaf Polyester Hybrid Composites Using Sodium Laulryl Sulfate Treatment The aim of this study is to investigate the effect of alkali and SLS (Sodium Lauryl Sulphate) treatment on Banana/Kenaf Hybrid composites and woven hybrid composites. The fibers are treated with 10% of sodium hydroxide (NaOH) and 10% Sodium Lauryl Sulfate (SLS) for 30 minutes. Woven banana and kenaf fiber reinforced unsaturated polyester (USP) composites were fabricated by moulding technique. The fiber content in the composite is kept constant to 40 %. The variation in the Mechanical properties (Tensile, Flexure and Impact strength) and morphological changes are studied. Hybrid composites; Banana fiber Kenaf Fiber Polymer; SLS https://mpm.spbstu.ru/article/2009.11.4/ MPM_8_2_P04.pdf

RAR RUS 174-199 Institute of Problems of Mechanical Engineering RAS I.A. Ovid’ko И.А.

St.Petersburg, Russia

Theories of Grain Growth and Methods of Its Suppression in Nanocrystalline and Polycrystalline Materials In this review, classical theories of grain growth in single-phase nanocrystalline materials are briefly presented. Theoretical models and specific features of grain growth process in nanocrystalline materials under thermal treatment and plastic deformation are discussed. Also, methods for stabilization of nanocrystalline structures (against grain growth) are briefly presented. grain growth polycrystals nanocrystalline materials deformation https://mpm.spbstu.ru/article/2009.11.5/ MPM_8_2_P05-Rus.pdf