Investigation of the Properties of Powder Materials Using Computer Modeling

2021 ◽  
Vol 1038 ◽  
pp. 33-39
Author(s):  
Viktoriya Pasternak ◽  
Lyudmila Samchuk ◽  
Nataliia Huliieva ◽  
Igor Andrushchak ◽  
Artem Ruban
Keyword(s):  
Fractional Composition ◽  
Average Particle Size ◽  
Three Dimensional ◽  
Average Diameter ◽  
Powder Materials ◽  
Average Particle ◽  
Inhomogeneous Materials ◽  
Cross Sectional ◽  
Powder Particles ◽  
Granulometric Characteristics

Granulometric characteristics of structurally inhomogeneous materials based on full-scale mounds of a powder mixture of different fractional composition are established. Regularities of backfilling of powder particles of different shapes and sizes are revealed, and changes in the polydispersity of powder particles within each fraction are justified. It is proved that with a decrease in the average particle size of structurally inhomogeneous AlCu2 materials in a single fraction, the size spread relative to this value of other particles increases. The results of calculating the porosity of backfills with particles of various shapes (round, triangular, and square) depending on the cross-sectional area of the lobules are presented. A three-dimensional diagram is constructed that shows the relationships between the fractional composition of powder particles, their average diameter, and the degree of inhomogeneity of homogeneous bronze AlCu2.

scholarly journals STUDY PARTICLE SIZE DISTRIBUTION OF ERODING POWDER LEAD BRONZES OBTAINED IN DISTILLED WATER

2018 ◽  
Vol 22 (4) ◽  
pp. 42-49
Author(s):  
E. V. Ageev ◽  
A. S. Pereverzev ◽  
A. S. Osminina ◽  
I. Yu. Grigorov
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
Discharge Zone ◽  
Powder Materials ◽  
Average Particle ◽  
Distilled Water ◽  
Powder Particles ◽  
Local Exposure ◽  
Finely Dispersed Powder ◽  
Powder Lead

The article is devoted to the current problem of processing waste of conductive materials, in particular lead bronze, which accumulates in large quantities at enterprises. A promising method for processing any conductive material, characterized by wastelessness, ecological purity of the process, and low energy costs, is the method of electroerosive dispersion. The essence of the method of electroerosive dispersion is the destruction of current-conducting material as a result of local exposure to short-term electrical discharges between the electrodes. In the discharge zone, under high temperatures, heating, melting and partial evaporation of the material occurs, resulting in the formation of finely dispersed powder particles. At the same time, the electrical parameters of the installation will affect the productivity of the process for obtaining powder materials: the voltage at the electrodes, the capacitance of the discharge capacitors, and the repetition rate. The article presents the results of the analysis of particles of powdered lead bronze obtained by the method of electroerosive dispersion in distilled water from wastes, using the laser analyzer of particle sizes "Analysette 22 NanoTec". It has been experimentally established that the average particle size of powdered lead bronze is 9.73 μm, the arithmetic value is 9.731 μm. It was also found that the elongation coefficient (elongation) of particles with a size of 7.188 μm is 1.50.

Preparation and Antibacterial Performances of Electrocatalytic Zinc Oxide Nanoparticles with Diverse Morphologies

2021 ◽  
Vol 17 (9) ◽  
pp. 1824-1829
Author(s):  
Junlin Li ◽  
Xiangfei Li ◽  
Dong Liang ◽  
Xiaojuan Zhang ◽  
Qing Lin ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Surface Area ◽  
Zinc Oxide Nanoparticles ◽  
Average Particle Size ◽  
Three Dimensional ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Zno Nps

This study exploits the potential of zinc oxide nanoparticles (ZnO-NPs) with diverse morphologies as catalysts and antibacterial agent. Spherical ZnO-NPs, rod-shaped ZnO-NPs and flower-shaped ZnO-NPs were prepared by microemulsion method, solvent heat method and hydrothermal method, respectively. The structural characterizations of samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. XRD results revealed the formation of spherical ZnO-NPs, rod-shaped ZnO-NPs and flower-shaped ZnO-NPs were all wurtzite crystal structure. SEM results showed that spherical ZnO-NPs had an average particle size of 30–40 nm, rod-shaped ZnO-NPs were about 500 nm long and 100 nm wide with obvious hexagonal crystals. Flower-shaped ZnO-NPs had a three-dimensional appearance with obvious petals. Results of electrochemical HER (Hydrogen evolution reaction) experiments revealed that spherical ZnO-NPs exhibited the highest electrocatalytic activity at the lowest potential voltage due to their largest specific surface area. The antibacterial property of ZnO-NPs samples were studied by the optical density method and disc diffusion method. All samples had antibacterial effects against E. coli. and flower-shaped ZnO-NPs showed the best antibacterial activity due to the largest surface area in comparison with spherical ZnO-NPs and rod-shaped ZnO-NPs, which promised the maximum Zn2+ release as bactericide mechanism that registered in the case of different ZnO-NPs morphologies.

Changes in Particle Size Distributions on a Fixed Bed of Granular Activated Carbon

1986 ◽  
Vol 18 (1) ◽  
pp. 31-42 ◽  
Author(s):  
E. A. Shpirt ◽  
K. T. Alben
Keyword(s):  
New York ◽  
Particle Size ◽  
Activated Carbon ◽  
Average Particle Size ◽  
Fixed Bed ◽  
Treatment Plant ◽  
Granular Activated Carbon ◽  
Water Treatment Plant ◽  
Average Diameter ◽  
Average Particle

The particle size distribution at different bed depths of a fixed bed of granular activated carbon (GAC) has been monitored during 50 weeks of a pilot column run at the Waterford, New York potable water treatment plant. Initial backwashing resulted in significant stratification of GAC in the column: larger particles (average diameter 1.18 mm) settled in the bottom of the column (105 cm), and smaller particles (average diameter 0.97 mm) were concentrated near the top (24 cm), compared to samples of unstratified virgin Calgon F400 (average diameter 1.09 mm). During column loading and initial backwashing, more fines were created than were present in the virgin GAC (average 6.5% of GAC fines in the > 40 mesh fraction, compared to only 0.3% in the > 40 mesh fraction for virgin Calgon F400). After 50 weeks of service there was an overall trend toward a smaller average particle size (0.9 mm) with development of a more regular pattern of bed stratification (1.08 mm at the bottom and 0.75 mm at the top). These changes are attributed to breaking of large particles (12-20 mesh) and creation of intermediate size particles (20-30 and 30-40 mesh).

Geopolymer Microstructure and Hydration Mechanism of Alkali-Activated Fly Ash-Based Geopolymer

2011 ◽  
Vol 374-377 ◽  
pp. 1481-1484 ◽  
Author(s):  
Yao Jun Zhang ◽  
Hai Hong Li ◽  
Ya Chao Wang ◽  
De Long Xu
Keyword(s):  
Electron Microscope ◽  
Fly Ash ◽  
Scanning Electron Microscope ◽  
Average Particle Size ◽  
Three Dimensional ◽  
Alkaline Condition ◽  
Average Particle ◽  
Hydration Mechanism ◽  
Alkali Activated ◽  
Scanning Electron

The microstructure and hydration mechanism of alkali-activated fly ash-based geopolymer were studied by means of scanning electron microscope (SEM) coupled with energy dispersive X-ray analysis (EDXA) and field emission scanning electron microscope (FESEM). The FESEM photomicrographs indicted that the fly ash-based geopolymer showed three dimensional frameworks with an average particle size of 50 nm. EDXA results demonstrated that the Na-PSS type geopolymer was produced via the disintegration of Si-O-Al and Si-O-Si chemical bonds and the polycondensation reaction between [SiO4]4-and [AlO4]5- tetrahedrons in spherical fly ash particles under alkaline condition.

Investigating the Structure and Properties of the AlSi10Mg Alloy Manufactured by Means of Selective Laser Melting

2020 ◽  
pp. 71-85
Author(s):  
A.K. Karavaev ◽  
Yu.A. Puchkov
Keyword(s):  
Particle Size ◽  
Heat Affected Zone ◽  
Average Particle Size ◽  
Average Particle ◽  
General Corrosion ◽  
Pure Aluminium ◽  
Structure And Properties ◽  
Columnar Crystal ◽  
Sample Depth ◽  
Powder Particles

The paper investigates the structure and properties of samples made of ASP-25 AlSi10Mg, a Russian powder designed to replace expensive additive manufacturing powders of European origin featuring the same chemical composition. We detected that the particle size in the ASP-25 AlSi10Mg powder varies in the range of 7 to 50 μm, the average particle size being 23 μm for the standard deviation of 9.15 and dispersion of 83.7. On the surface of powder particles, we observed smaller satellite particles, individual aggregates, and particles of pure aluminium. We detected the following at the transition boundary between adjacent tracks: a columnar crystal zone and a heat-affected zone consisting of three layers of large, medium and small grains generated as a result of varied cooling conditions. These grains display different silicon lattice thicknesses along their boundaries. We detected no critical size pores (over 15 μm) or burning in the heat-affected zone. The fact that microhardness increases towards the sample edges and is non-monotonic over the transverse section is due to a range of factors acting simultaneously to create non-uniform temperature and force fields that cause differences in conditions of structure formation. Fractography studies of fractures in the AlSi10Mg alloy showed that the nature of failure varies along the sample depth. The central part of the sample, which is subjected to the highest thermal effects, shows clear signs of viscous failure along the main cracks developing along the boundaries of construction layers. We showed that the AlSi10Mg alloy is more resistant to pitting corrosion and general corrosion than the AK9сh (AK9ч) alloy

scholarly journals Influence of Glass Powder Size Sorting on Properties of Composite Systems

2016 ◽  
Vol 47 (1) ◽  
pp. 25-31
Author(s):  
K. Dědičová ◽  
P. Valášek
Keyword(s):  
Glass Powder ◽  
Adhesive Bonding ◽  
Raw Materials ◽  
Average Particle Size ◽  
Polymeric Materials ◽  
Average Particle ◽  
Powder Size ◽  
Size Sorting ◽  
Powder Particles ◽  
Size Of Particles

Abstract Glass powder ranks among the secondary raw materials, which can be used in the interaction with polymeric materials. In the present experiment the polymeric/epoxy particle composite with different sizes of glass powder particles is described. Such utilization of recyclable materials is environmental-friendly and should be preferred. The size of particles forming the filler of the described composites is one of the key characteristics affecting the mechanical properties. Due to the properties of the systems filled with glass powder, these materials can potentially be used in agriculture (renovations, adhesive bonding, cementing, etc.). In the experiment, glass powder was dimensionally sorted through sieves. Three fractions of glass powder with particles size of 0−30, 30−50, and 50−90 μm were created and utilized, the average particle size being 18.7, 38.7, and 72.6 μm, respectively. The interaction of the 18.7 μm particles did not lead to a statistically significant decrease of shear strength values in the interval 0−20 vol.%. The presence of glass powder, however, in all cases decreased tensile strength.

Fine Copper Powders Production

2021 ◽  
Vol 410 ◽  
pp. 418-424
Author(s):  
Natalia E. Agarova ◽  
Lyubov M. Yakovleva ◽  
Roman S. Voinkov ◽  
Konstantin L. Timofeev
Keyword(s):  
Average Particle Size ◽  
Chloride Ions ◽  
Average Particle ◽  
Air Classification ◽  
Operating Modes ◽  
Electrolytic Copper Powder ◽  
Copper Powders ◽  
Powder Particles ◽  
Fine Copper

The article is devoted to the description of a method for producing electrolytic copper powder with an average particle size of 3 to 10 μm. In order to increase the proportion of the finely dispersed fraction during the electrolysis process, the composition of the electrolyte was changed. In particular, the content of chloride ions was increased from 6 to 53 mg/dm3. After the growth of the powder in industrial baths, its subsequent drying and sieving on vibrating screens, samples were obtained with a fraction of 5 μm content in the range from 3 to 38 %. Additionally, air classification of powders was carried out at various speeds of the classifier rotor from 800 to 2000 rpm. Based on the results of the study, the optimal ranges of the specific surface area and the size of the initial powder particles before classification, as well as the composition of the electrolyte and the operating modes of the classifier, were determined.

scholarly journals Effect of mechanical activation duration on combustion parameters of Al-Mg-based high-energy systems

2018 ◽  
Vol 243 ◽  
pp. 00013 ◽  
Author(s):  
Sergey Sokolov ◽  
Yana Dubkova ◽  
Alexander Vorozhtsov ◽  
Valery Kuznetsov ◽  
Vladimir Promakhov ◽  
...  
Keyword(s):  
Mechanical Activation ◽  
Burning Rate ◽  
Average Particle Size ◽  
Diffraction Method ◽  
High Energy ◽  
Planetary Mill ◽  
Powder Materials ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Combustion Heat

The paper studies dispersion, oxidation degree, burning rate and combustion heat in high-energy mixtures obtained from of Al-Mg powder materials depending on the duration of mechanical activation in a planetary mill. According to dispersion analysis by laser diffraction method, 3 h mechanical activation gives Al-Mg particles with average particle size of 30 μm compared to 180 μm particles obtained after 2 h activation. Thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) were used to record TG/DSC curves and measure burning rate and combustion heat for synthesized powders in comparison with engineered Al-Mg powder PAM−4 (Novosverdlovsk Metallurgical Company, Yekaterinburg, Russia). It has been found that the injection of 6 h mechanically activated Al-Mg powder into high-energy compositions leads to 24 and 45% increase of burning rate and combustion heat compared to the compositions without additive.

scholarly journals Thermal Conductivity of a Monolayer of Exfoliated Graphite Nanoplatelets Prepared by Liquid-Liquid Interfacial Self-Assembly

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Jinglei Xiang ◽  
Lawrence T. Drzal
Keyword(s):  
Thermal Conductivity ◽  
Self Assembly ◽  
Average Particle Size ◽  
Peak Shift ◽  
Exfoliated Graphite ◽  
Average Particle ◽  
Graphite Nanoplatelets ◽  
Cross Sectional ◽  
Packed Structure ◽  
Exfoliated Graphite Nanoplatelets

A monolayer film composed of exfoliated graphite nanoplatelets (xGnPs) was extracted from a chloroform-water interface and supported on a glass substrate. The nanoplatelets are interconnected at the edges without overlapping forming a very densely packed structure with uniform thickness. Micro-Raman spectroscopy with a 50 mW 532 nm laser generating heat at the center of a xGnP sample was used to probe the thermal conductivity of the xGnP monolayer at different power levels. The Raman G peak shift of graphite was used to record the local temperature rise in the monolayer. The cross-sectional area of heat conduction is determined by the thickness of individual nanoplatelets. A UV-Vis spectrometer was used to measure the absorption of light by the monolayer. Depending on the interface density, the thermal conductivities are around 380 W/m K and 290 W/m K for monolayers with average particle size of 10 μm and 5 μm, respectively.

Sign in / Sign up

Export Citation Format

Share Document