Nanostructural Engineering of Steel

The concept of microstructural engineering of steels is well established and is the basis for a wide range of processes and products. Recently, though, there has been increasing emphasis in developing microstructures that have submicron length scales and also in understanding in far greater detail the structures and solute effects that are occurring at the nanoscale. In this review it is proposed that we are heading towards the situation where we are applying nanostructural engineering concepts in the development of new steels. A range of examples are given as well as a discussion of the potential impact of new processing routes. Clearly the future advances will be driven through improved characterization methods, such as atom probe tomography, in combination with advanced modeling

Laser spectoscopy of Mandelstems - Brillian scattering in aqueous nonelectrolyte solutions

In this work we developed a method of laser spectroscopy to study the frequency shift of Mandelshtam-Brillouin components in the fine structure of Reyleigh line, which are origin due to the pressure fluctuations. The method allows to study a character of hypersound (~109 Hz)propagation in a critical region of a thermodynamic instability. Analysis of a complex of experimental material , presented in the paper, allows one to conclude that in aqueous solutions of non-electrolytes at critical concentration there is a whole structural transformations in solutions at the singular point temperature in “temperature-concentration” coordinate

Electromagnetic wave diffraction by bi-periodic thin conductive grating

© 2015 I.E. Pleshchinskaya, N.B. Pleshchinskii and I.V. Sabirov. It has been proved that the electromagnetic wave diffraction problem by bi-periodical grating of thin conductive strips can have only one solution. Therefore, only Floquet wave can appear by the diffraction of the plane wave by the grating. The diffraction problem is reduced to regular infinite set of linear algebraic equations by method of integral- summatorial identities

Structure-property relations of metallic materials with multiscale microstructures

Nanostructured metals have higher strength than those of the coarse grained metals but suffer from the extremely limited ductility. Development of the multiscale microstructures can improve the ductility of these high strength materials due to the introduction of a specific range of grain sizes in micro level. The present work relates the multiscale microstructures in metals to their overall structure properties using a fractal theory and the modified mean-field method, where three microstructural parameters are introduced and thus mechanical properties such as strength and ductility are presented as a function of these microstructural parameters. Meanwhile, with the applications of the finite element method, the multiscale unit cell approach is also critically developed and applied with a focus on predicting the related stress-strain relations of the metals with multiscale microstructures. For verification of these proposed theoretical and numerical algorithms, the mechanical properties of the pure copper with three-grain microstructures are investigated and the results from FEA and theoretical solutions have a reasonable agreement

Study of Deformations Field in the Working Zone of Vertical Milling Machine

© 2017 The Authors. Published by Elsevier Ltd. The paper examines the questions of the static elastic deformation development during the machining with milling machines. It discusses the issues of "machine - tool - instrument - workpiece"system modelling aiming at providing the preliminary assessment of elastic deformations during the processing, which gives an opportunity to prevent defect appearance. The deformation distribution is detected for the cases when the cutting area is positioned in different points of working area of the machine. The changes of deformations for different cutting pattern are analysed, a method of determination of main axes rigidity is considered based on that. The results show that the deformation of the technological system depends not only on the geometry of the basic parts and junctions but also on their location. The modelling the whole technological system is required. Only in this case selecting the optimal tool and its location to achieve the required quality of processing is possible

The algorithm of the expert system of APCS (automated process control systems) tests

description of a general algorithm of the expert system of APCS tests is presented

The state of benthic communities and water quality evaluation in the Cheboksary Reservoir

Present-day quantitative and qualitative characteristics of the Cheboksary Reservoir have been investigated, and data on the biological diversity of benthic organisms have been compared to those of hydrobiological studies carried out in the region prior to the reservoir construction. The reservoir bottom communities include 75 species and forms of benthos. The reservoir water quality has been evaluated using different methods, including the determination of the degree of morphological structure abnormalities in chironomid larvae, regarded as sublethal indicators of bottom sediment pollution with toxic substances. © 2004 MAIK "Nauka/Interperiodica"