Production of heat-resistant EP220 and EP929 alloys by high-temperature treatment of melt

Analysis of samples of EP220 and EP929 alloys in the liquid and solid state permits the determination of the parameters for high-temperature melt treatment in their production. On heating to specific temperatures, the structure of the liquid alloys moves closer to equilibrium. In the solidification of such melt, the cast metal formed is characterized by finer grain structure, greater dispersity of the dendrites, and greater density and microhardness of the matrix. Industrial adoption of high-temperature melt treatment will improve plasticity, increase the long-term strength, and boost the product yield. The proposed technology does not fully utilize the potential of the alloy structure obtained after high-temperature melt treatment. The effect may be amplified by more prolonged holding of the melt at 1650°C and by optimization of the vacuum-arc heating, deformation, and heat treatment, in the light of the structural changes in the experimental samples of solid metal. © 2013 Allerton Press, Inc

Approximating heat resistance of nickel-based superalloys by a sigmoid

The nickel-based superalloys are unique materials with complex doping applied to manufacturing the gas turbine engine parts. The alloys show resistance to mechanical and chemical degradation under high pressure, high temperature, and long-term isothermal exposures. One of the main alloys' service properties is the heat resistance. Numerically, it is expressed in the tensile strength values (MPa). Simulation of the heat resistance behavior is an important engineering task, which would significantly simplify the analysis of existing and designing the new alloys. In this paper, we use results of the heat resistance simulation by an artificial neural network, as well as, experimental data for approximating the changes in the heat resistance vs isothermal exposures expressed in the complex Larson-Miller parameter by a sigmoidal function. © 2020 American Institute of Physics Inc.. All rights reserved

Modeling the heat resistance of nickel-based superalloys by a deep learning neural network

The nickel-based superalloys are unique materials with complex alloying used in the manufacture of gas turbine engines. The alloys exhibit excellent resistance to mechanical and chemical degradation under the high loads and long-term isothermal exposures. The main service property of the alloy is its heat resistance, which is expressed by the tensile strength. Simulation of changes in the heat resistance is an important engineering problem, which would significantly simplify the design of new alloys. In this paper, we apply a deep learning neural network to predict the tensile strength values and to compare the predictive ability of the proposed approach. Also, the results are presented of the feed-forward neural network accounting changes in heat resistance vs isothermal exposures that are expressed in the complex Larson-Miller parameter. © 2020 American Institute of Physics Inc.. All rights reserved

Точная эмпирическая формула определения плотности жаропрочных никелевых сплавов

The density of a substance is one of its main physical characteristics. This is especially true for materials used in aviation, where the mass of each structural element should be minimized as much as possible. When developing new structural materials, for example, heat-resistant nickel alloys, which are widely used in the manufacture of gas turbine engine parts, it is extremely important to have a reliable and accurate method for assessing the density of the material being developed. Until now, no unified method has been proposed for calculating the density of heat-resistant nickel alloys. The paper reviews the available approaches to assessing the density of alloys and proposes a new formula that allows one to calculate the density of an alloy with a high accuracy based on the information on its composition. The proposed approach takes into account the spatial fcc structure of heat-resistant nickel alloys as well as the molar mass and molar volume of the elements that form the alloy. To check the accuracy of the calculations, a database of 69 heat-resistant nickel alloys was collected, containing information on the composition of the alloys and their known density. According to the proposed formula, as well as using some other known approaches, the density for the alloys from the database was calculated. The calculation results showed that the proposed method provided the best accuracy among all considered ones: the standard deviation of the calculated values from the real ones for the entire sample was 0.1%, the mean values and medians practically coincide. In addition, the calculation errors are normally distributed and have an average value of −0.0001. The existing methods give a minimum error of 1.2%, thus, the proposed approach improved the accuracy of calculating the density of heat-resistant nickel alloys by about an order of magnitude, which is a significant result both from the point of view of the general scientific approach and from the point of view of engineering practice. Taking into account the results obtained, the proposed formula can be widely used in the development of new and modification of existing heat-resistant nickel alloys. © 2021, Institute for Metals Superplasticity Problems of Russian Academy of Sciences. All rights reserved

Printing paper as a reflector with idealized properties: How to link the paper industry and printing art

Whiteness is one of the most important characteristics of a printing paper. There is a stable relationship between the printed and optical properties of the paper. At the same time, the understanding of whiteness in the papermaking and printing industries is significantly different. Such miscommunication negatively affects the quality of printed products, since the choice of a suitable paper (or cardboard) is difficult to a certain extent. One of the ways to get out of this situation is to create a simple and clear computational model of the white paper, which would not depend on any physical standards. The model would help when conducting the input control in printing plants and would allow one to establish communication between industries. This work is devoted to the description of such a model. © 2020 American Institute of Physics Inc.. All rights reserved

The Influence of Melt State on Atomization Process and Quality of Powders on Iron and Nickel Base

The analysis of the results of physical and chemical properties and structure investigation in liquid multicomponent steels and alloys indicates that after melting their state is generally not in equilibrium. Heating to the critical temperatures helps the system to transform into the equilibrium state or the state close to it. Melt preparing before atomization affects the process of liquid metal dispersion and helps to improve the structure and properties of the powder. The optimum melt preparing technology before atomization leads to formation the dispersion dendritic structure, optimum morphology, quantity and size of primary and eutectic phases in the powders particles and increase in properties. © 2008 IOP Publishing Ltd

A substantial scale invariant quantiative evaluation of a font based on ideas of fractal geometry

Для оценки пространственных особенностей шрифтовых рисунков предложено использовать масштабно инвариантный показатель, основанный на идеях фрактальной геометрии. Шрифт рассматривается как связное геометрическое множество векторных графических объектов и к нему применяется определение нормализованной компактности. Для вычисления периметра и площади векторного объекта использован VBA макрос Curveinfo векторного графического пакета CorelDraw. Был разработан специальный макрос, который автоматизирует процесс разбиения произвольного количества текстовых объектов на набор векторных объектов представляющих из себя абрисы букв и внутрибуквенные просветы. Выборка: 21 шрифт, размеры 12 и 18 пт; из них 9 шрифтов без засечек, 11 шрифтов с засечками и один скриптовый шрифт. Результаты и измерений и расчетов показали масштабную инвариантность нормализованной компактности и возможность использования этого показателя как численной характеристики и основания для классификации шрифтов.For an assessment of spatial features of font drawings it is offered to use on a substantial scale invariant indicator based on ideas of fractal geometry. The font is considered as a coherent geometrical set of vector graphic objects and determination of the normalized compactness is applied to it. For calculation of perimeter and the area of vector object VBA a macro of Curelinfo of a vector graphic CorelDraw package is used. The special macro which automates process of splitting any amount of text objects into a set of vector objects outlines of the letters and inside the alphabetic gleams which are selection was developed: 21 fonts, sizes 12 and 18 point; from them 9 sans-serif fonts, 11 serif types and one scripting font. Results and measurements and calculations showed large-scale invariancy of the normalized compactness and possibility of use of this indicator as numerical characteristic and basis for classification of fonts