scholarly journals Production of corundum armored ceramics

2021 ◽  
Vol 2131 (4) ◽  
pp. 042032
Author(s):  
P Pletnev ◽  
Yu Nepochatov
Keyword(s):  
Eutectic Mixture ◽  
Physical And Mechanical Properties ◽  
Al2o3 Content ◽  
Physicochemical Processes ◽  
Zirconium Oxides ◽  
Collective Recrystallization ◽  
Model Idea ◽  
Α Al2o3 ◽  
High Level ◽  
Crystalline Matrix

Abstract The purpose of this study was to develop the compositions and technology of corundum armored ceramics with high ballistic characteristics based on aluminum oxide with an α-Al2O3 content of more than 99 wt.%. The results of the study of the physicochemical processes of obtaining corundum ceramics modified with complex additives consisting of magnesium - aluminosilicate eutectic mixture and oxides of magnesium, yttrium, titanium, zirconium are presented. The introduction of complex additives into the composition of corundum ceramics provides a significant reduction (100-150°C) of the sintering temperature of the product. In this case, additives of yttrium and zirconium oxides contribute to the formation of a uniform-grained microstructure of ceramics, and in the case of adding titanium oxide, a collective recrystallization of corundum grains is noted. The use of small additives (0.3-0.5 wt.%) of magnesium and yttrium oxides together with a eutectic mixture in the compositions of corundum ceramics based on high-quality alumina contributes to the formation of a uniform-grained, dense structure of the material and giving it a high level of physical and mechanical properties as a result of directional the action of each component of the additive on the physicochemical processes of phase formation of the crystalline matrix. A model idea of the mechanism of action of additives on the formation of the microstructure of ceramics during stage-by-stage heating from 1350 to 1650°C in the sintering mode of products is presented. The developed compositions and technologies of corundum armored ceramics have a production focus and implementation in practice.

Technologies of Nanomodification of Low-Carbon Low Alloyed Steels

2010 ◽  
Vol 638-642 ◽  
pp. 3123-3127
Author(s):  
V.A. Malyshevsky ◽  
E.I. Khlusova ◽  
V.V. Orlov
Keyword(s):  
Large Scale ◽  
Physical And Mechanical Properties ◽  
Metallurgical Industry ◽  
Low Alloy Steels ◽  
Scale Production ◽  
Low Carbon ◽  
Fine Grained ◽  
Interphase Boundaries ◽  
Alloy Steels ◽  
High Level

Metallurgical industry can be considered as a field most accommodated for perception of nano-technologies, which in the near future will be able to provide large scale production and high level of investments return. Specially noted should physical and mechanical properties of nano-structured steels and alloys (strength, plasticity, toughness and so on) which will cardinally excel characteristics of respective materials developed using conventional technologies. Investigations have shown that basic principles of selection of a structure up to nano-level for low-carbon low-alloy steels can be put forward, that is: 1) morphological similarity of structural components, pre-domination of globular type structures due to reduction in carbon components and rational alloying; 2) formation of fine-dispersed carbide phase of globular morphology; 3) exclusion of lengthy interphase boundaries; 4) formation of fragmented structure with boundaries close to wide-angle ones, which inherited structure of fine-grained deformed austenite.

Preparation and Microstructure of Bauxite Ceramic Microsphere

2007 ◽  
Vol 336-338 ◽  
pp. 1124-1126
Author(s):  
Xiao Su Cheng ◽  
Ling Ke Zeng ◽  
Xiu Yan Li ◽  
Wen Yan Sheng ◽  
An Ze Shui ◽  
...  
Keyword(s):  
Raw Materials ◽  
Xrd Analysis ◽  
Al2o3 Content ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Main Crystalline Phase ◽  
Ceramic Microsphere ◽  
Α Al2o3 ◽  
Chinese Bauxite

In this paper, microspheres were prepared by using Chinese bauxite as raw materials through centrifugal spray drying method. The microstructure and composition of ceramic microsphere were investigated by X-ray diffraction, scanning electron microscope and X-ray energy spectrum. The particle size was 10~100#m. The XRD analysis reveals that the main crystalline phase of the ceramic microsphere were α-Al2O3 and mullite (3Al2O3•2SiO2). The Al2O3 content (chemical composition) of the microspheres was little more than 70%, and the molar ratio of Al2O3/SiO2 was near to the molar ratio of alumina and silica of mullite.

scholarly journals ЕКСПЛУАТАЦІЙНІ ВЛАСТИВОСТІ ГОТЕЛЬНИХ МАХРОВИХ РУШНИКІВ

2021 ◽  
pp. 43-51
Author(s):  
А. С. Паршин ◽  
С. І. Арабулі ◽  
А. Т. Арабулі
Keyword(s):  
Mechanical Properties ◽  
Materials Science ◽  
Experimental Studies ◽  
Statistical Processing ◽  
Physical And Mechanical Properties ◽  
Basic Principles ◽  
Textile Materials ◽  
Textile Fabrics ◽  
High Level ◽  
Experimental Researches

Assessment of the providing level of hotel facilities by quality terry towels based on a comprehensive study of the operational properties of terry textile fabrics. Methodology. Theoretical and experimental researches are based on the basic principles of textile materials science. During experimental studies, modern methods were used to determine the physical and mechanical properties of textile materials, as well as methods of mathematical planning and statistical processing of the experimental results. Results. The state and norms for the provision of hotel facilities in Ukraine with terry towels are given. The assortment of hotel terry towels has been analyzed. The main factors of the formation of a modern assortment of textile materials for hotel terry towels are considered. The focus is on the classic range of double nap terry fabrics for hotel towels. The analyses of the physical and mechanical properties of modern fabrics for hotel towels are present. Indicators characterizing the interaction of textile with liquid moisture have been experimentally determined. The paper presents the results of determining the wear resistance of fabrics after 1, 5 and 10 cycles "wash-ironing". Scientifi c novelty. The data of the physical and mechanical properties of the classic assortment of textile materials for hotel terry towels are systematized. It has been experimentally proven that the assortment of cotton terry textile materials, which is currently available on the Ukrainian market and is used for the manufacture of hotel terry towels, provides a high level of comfort and durability of towels. Practical value. The modern assortment of textile materials for hotel terry towels is analyzed, taking into account the peculiarities of the operational situation of consumption.

Preparation and Phase Analysis of Fe-SiAlON-MoSi2 Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1123-1125 ◽  
Author(s):  
Jing Zhou Yang ◽  
Zhao Hui Huang ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
Xiao Xian Wu
Keyword(s):  
Phase Analysis ◽  
Sintering Temperature ◽  
Al2o3 Content ◽  
Hexagonal Prism ◽  
Z Value ◽  
Α Al2o3 ◽  
Mosi2 Composite

Fe-SiAlON-MoSi2 composites were prepared using FeSi75, α-Al2O3, and MoSi2 powders as starting materials at 1400 oC, 1500 oC, 1600 oC and 1700 oC, respectively, for 3h in a flowing nitrogen under the pressure of 0.9MPa. The results showed that the main phases of Fe-SiAlON-MoSi2 composite were β-SiAlON with deferent Z-values, MoSi2, and Fe3Si. Z-value of the obtained β-SiAlON depanded on α-Al2O3 content and the sintering temperature. The morphology of SiAlON phase changed from fibre-like of low Z-value to hexagonal prism-like of high Z-value.

Stereological Microstructure Description of Structural SiC Ceramics as Composite Material

2010 ◽  
Vol 65 ◽  
pp. 130-134
Author(s):  
V. Rumyantsev ◽  
Andrey Osmakov ◽  
S. Boykov ◽  
V. Fishev
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Composite Ceramic ◽  
Generalized Equations ◽  
Adequate Description ◽  
Continuous Component ◽  
Discrete Component ◽  
Sic Ceramics ◽  
High Level ◽  
Composite Ceramic Material

Within unified stereological approach the silicon carbide-based ceramics SiSiC , SSiC, and LPSiC are treated as binary compositions, that despite certain structure ordering differences might be similarly described as comprising topologically continuous component (that provides the high level of physical and mechanical properties), and a discrete component. The paper demonstrates the necessity of using dimensionless criterial parameters for adequate description of the integral microstructure ordering level; said parameters including the characteristics of both continuous and discrete components of the composite ceramic material. Generalized equations are derived for compound stereological parameters of the discussed materials, along with statistically reliable approximations of the strength characteristics as functions of these parameters.

scholarly journals The significance of scanning electron microscopy (SEM) analysis on the microstructure of improved clay: An overview

2021 ◽  
Vol 13 (1) ◽  
pp. 197-218
Author(s):  
Nazile Ural
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Physical And Mechanical Properties ◽  
Sem Analysis ◽  
Clay Particles ◽  
Soil Microstructure ◽  
Before And After ◽  
Problematic Soils ◽  
High Level ◽  
Scanning Electron

Abstract This study aims to emphasize the importance of scanning electron microscopy (SEM) in explaining the differences in the physical and mechanical behaviors of the improved clays before and after improvement. Generally, clays appear as problematic soils in the construction area. The reasons for this can be low strength, high compressibility, high level of volumetric changes, and swelling potential. The behavior of clays may not always be interpreted according to their physical and mechanical properties. In such cases, analyses are carried out according to the microstructure of the clay. Among several microstructural analyzes, SEM is very important, because the soil microstructure formed by clay particles and additives can be observed. This work discusses the studies based on the microstructural properties of the improved clay with SEM analysis. As a result of the studies carried out, it has been seen that unexplained physical or mechanical behavior can be explained by the microstructural behaviors of clay particles and additives.

scholarly journals The process of controlling the mass of piece products on pneumatic devices

2019 ◽  
Vol 81 (1) ◽  
pp. 138-143
Author(s):  
V. K. Bityukov ◽  
I. A. Avcinov ◽  
N. V. Sukhanova
Keyword(s):  
Physical And Mechanical Properties ◽  
High Sensitivity ◽  
Support Surface ◽  
Characteristic Parameters ◽  
Specific Product ◽  
The Creation ◽  
Gas Layer ◽  
High Level ◽  
Gas Bearing

The principle of recognition based on the use of the properties of a thin gas layer and the supporting surface of equipment, which provided the creation of a number of universal devices capable of solving the problem of sorting and culling piece parts by weight. A promising method of recognition by the generalized criterion (specific load) is presented on the basis of which two new orientation criteria were obtained (the area of the support surface of the product and its mass) are obtained on the basis of this method. It is proved that the gas layer has a high sensitivity to changes in the characteristic parameters of products, i. e. is able to recognize them. There is a need to develop automatic sorting and rejection devices for a class of small piece products with implicit design features and having understated physical and mechanical properties, as they can not apply to traditional means of automation, loading and orientation operations with mechanical grips, weighing in the stream. There are significant difficulties in the culling of piece products with bevels, shells, etc., which led to the creation of devices that provide manipulation of a wide variety of sizes of specific products with a decrease in dry mechanical friction between the product and the bearing parts of the equipment. Classification of specific product types and configurations of circuits pneumatic devices that use the effects in the thin gas bearing strata (the working surfaces and air chambers, view their movements, technological capabilities). The bases of recognition of products by mass on a gas layer with the use of various working surfaces, which formed the basis for the creation of a number of new sorting devices with a high level of flexibility, are proposed..

scholarly journals CHANGE IN THE HYGROSCOPICITY OF PINE CORE WOOD IN A TREE TRUNK DAMAGED BY FIRE

2021 ◽  
Author(s):  
Aleksey Platonov ◽  
A. Popov ◽  
Svetlana Snegireva ◽  
Ekaterina Kantieva
Keyword(s):  
High Temperature ◽  
Practical Interest ◽  
Physical And Mechanical Properties ◽  
Middle Part ◽  
Hydroxyl Groups ◽  
Tree Trunk ◽  
Voronezh Region ◽  
Great Practical Interest ◽  
Partial Blocking ◽  
High Level

Fires have a significant impact on the structure and physical and mechanical properties of wood. The degree of this effect depends on the type of fire, its intensity and the duration of exposure to high temperature. The greatest impact on the wood occurs with a strong grassroots and general top fire. Gorenje fire is characterized by a high intensity of burning of forest floor and undergrowth, as well as the crown of trees. The effect of the high temperature of the fire on the tree trunk is different. As a result of the destruction of wood, there is a partial blocking of hydroxyl groups in the cellulose molecules and leads to a decrease in the hygroscopicity limit of wood. Of great practical interest is the change in the hygroscopicity of wood damaged by fire. The aim of this study is to determine the changes in the hygroscopicity of the core wood of Scots pine (Pinus sylvestris L.)after damage by a strong grassroots and general high-level fire. The studies were carried out on wood growing on the territory of the UOL in the Voronezh region, on samples of pine core wood cut from the clump, middle and apex parts of the trunk. It was experimentally established that the greatest decrease in the hygroscopicity of pine core wood occurred in the left part of the trunk, and the smallest in the middle part, after fire damage.

WAYS TO IMPROVE THE RELIABILITY AND DURABILITY OF RESPONSIBLE PARTS BASED ON ADVANCED MATERIALS AND TECHNOLOGIES

2020 ◽  
Vol 5 ◽  
pp. 46-54
Author(s):  
A.M. KOLOSOVSKIY
Keyword(s):  
High Performance ◽  
New Technologies ◽  
Physical And Mechanical Properties ◽  
Advanced Materials ◽  
Laser Application ◽  
Physical Methods ◽  
Promising Direction ◽  
Military Equipment ◽  
Coating Formation ◽  
High Level

The article discusses new technologies of production, repair of responsible parts of machines, as well as materials, the application of which allows ensuring a high level of reliability, durability and other important performance of military equipment. The current and promising direction in the field of creating high-performance coatings (as well as technologies of their application) with high physical and mechanical properties of responsible parts of mechanisms and machines is laser application and caking Nano powders, other advanced electro physical methods of coating formation with unique properties it is shown.

scholarly journals Using TeX Markup Language for 3D and 2D Geological Plotting

2021 ◽  
Vol 46 (1) ◽  
pp. 43-69
Author(s):  
Vasiliy Lemenkov ◽  
Polina Lemenkova
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Experimental Tests ◽  
Markup Language ◽  
Technical Application ◽  
Graphical Visualization ◽  
Compressibility Coefficient ◽  
High Level ◽  
2D And 3D ◽  
Logical Data

Abstract The paper presents technical application of TeX high-level, descriptive markup language for processing geological dataset from soil laboratory. Geotechnical measurements included equivalent soil cohesion, absolute and absolute deformation index, soil compressibility coefficient by time of immersion depth, exposure time to compressive strength to samples and physical and mechanical properties (humidity, density). Dataset was received from laboratory based experimental tests of the physical and mechanical properties of soils. Data were converted to csv table and processed by LaTeX. Methodology is based on LaTeX packages: {tikz}, {tikz-3dplot}, {tikzpicture}, {pgfplot}, {filecontetns}, {spy} for 3D plotting showing correlation in variables and descriptive statistical analysis based on the data array processing. Results demonstrated LaTeX scripts and graphics: 2D and 3D scatterplots, ternaries, bar charts, boxplots, zooming techniques detailing fragment of the plot, flowchart. Research novelty consists in technical approach of TeX language application for geo- logical data processing and graphical visualization. Engineering graphics by TeX was demonstrated with screenshots of the codes used for plotting.

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