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

The Melt Heat Treatment and the Structural Changes in ZhS6U and Inconel 718

One of the most curious phenomena observed in metal melts is the temperature-induced liquid-liquid structural changes. As a result of the thermal treatment lead to LLT, a more equilibrium and micro-uniform melt consisting of atomic associations is formed. In nickel alloy melts, the changes that have occurred are irreversible and have a significant effect on the formation of the final structure and the mechanical properties of the metal in the solid state after its crystallization. In addition, they are the starting point for the scientific substantiation of new technological modes of smelting and heat treatment of alloys, which further improve their operational properties, as well as reduce metallurgical defects and production waste, and rational use of expensive ligands. All this in general will lead to a significant increase in the performance of melts and metal products. Our work is devoted to the experimental confirmation of the LLT transition in two common nickel-based alloys by a non-invasive electromagnetic method. © Published under licence by IOP Publishing Ltd

Modeling of surface dust concentration in snow cover at industrial area using neural networks and kriging

Modeling of spatial distribution of pollutants in the urbanized territories is difficult, especially if there are multiple emission sources. When monitoring such territories, it is often impossible to arrange the necessary detailed sampling. Because of this, the usual methods of analysis and forecasting based on geostatistics are often less effective. Approaches based on artificial neural networks (ANNs) demonstrate the best results under these circumstances. This study compares two models based on ANNs, which are multilayer perceptron (MLP) and generalized regression neural networks (GRNNs) with the base geostatistical method-kriging. Models of the spatial dust distribution in the snow cover around the existing copper quarry and in the area of emissions of a nickel factory were created. To assess the effectiveness of the models three indices were used: the mean absolute error (MAE), the root-mean-square error (RMSE), and the relative root-mean-square error (RRMSE). Taking into account all indices the model of GRNN proved to be the most accurate which included coordinates of the sampling points and the distance to the likely emission source as input parameters for the modeling. Maps of spatial dust distribution in the snow cover were created in the study area. It has been shown that the models based on ANNs were more accurate than the kriging, particularly in the context of a limited data set. © 2017 Author(s)

Font legibility of electronic media using an eye-tracker

Статья посвящена шрифтовой разборчивости в современной типографике, как на печатных, так и на электронных носителях. Также рассмотрены труды ученых из Германии в методике оценки разборчивости шрифтов и немецкий стандарт DIN1450. Предложены методы улучшения разборчивости шрифта и ее оценки в газете и журнале, на электронных носителях, а также официальных документах. Рассмотрено влияние геометрических параметров шрифта на его удобочитаемость. Произведено сравнение этих методик, что в дальнейшем должно помочь типографам и дизайнерам при выборе шрифтовой гарнитуры. Также с помощью метода айтрекинга произведены исследования, описывающие движение газ при чтении текста.Article is devoted to font legibility in modern typographic, both on printing and on electronic media. Works of scientists from Germany in a technique of an assessment of font legibility and the German DIN1450 standard are also considered. Methods for improvement of font legibility and its assessment in newspapers and magazines, on electronic media, and also in official documents are offered. Influence of geometrical parameters of a font on its legibility is considered. Comparison of these techniques that further is to help printers and designers at a choice of a font is made. The research describing the eye movement during reading by means of an eye-tracking method was conducted

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