scholarly journals Influence of the Shape of Copper Powder Particles on the Crystal Structure and Some Decisive Characteristics of the Metal Powders

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 56 ◽  
Author(s):  
Ljiljana Avramović ◽  
Vesna M. Maksimović ◽  
Zvezdana Baščarević ◽  
Nenad Ignjatović ◽  
Mile Bugarin ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Structural Characteristics ◽  
Metal Powders ◽  
X Ray Diffraction ◽  
Applied Current ◽  
X Ray ◽  
Powder Particles ◽  
Micro Structures ◽  
Spherical Grains

Three different forms of Cu powder particles obtained by either galvanostatic electrolysis or a non-electrolytic method were analyzed by a scanning electron microscope (SEM), X-ray diffraction (XRD) and particle size distribution (PSD). Electrolytic procedures were performed under different hydrogen evolution conditions, leading to the formation of either 3D branched dendrites or disperse cauliflower-like particles. The third type of particles were compact agglomerates of the Cu grains, whose structural characteristics indicated that they were formed by a non-electrolytic method. Unlike the sharp tips that characterize the usual form of Cu dendrites, the ends of both the trunk and branches were globules in the formed dendrites, indicating that a novel type of Cu dendrites was formed in this investigation. Although the macro structures of the particles were extremely varied, they had very similar micro structures because they were constructed by spherical grains. The Cu crystallites were randomly oriented in the dendrites and compact agglomerates of the Cu grains, while the disperse cauliflower-like particles showed (220) and (311) preferred orientation. This indicates that the applied current density affects not only the morphology of the particles, but also their crystal structure. The best performance, defined by the largest specific surface area and the smallest particle size, was by the galvanostatically produced powder consisting of disperse cauliflower-like particles.

scholarly journals Synthesis of magnesium carbonate hydrate from natural talc

2020 ◽  
Vol 18 (1) ◽  
pp. 951-961
Author(s):  
Qiuju Chen ◽  
Tao Hui ◽  
Hongjuan Sun ◽  
Tongjiang Peng ◽  
Wenjin Ding
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Crystal Growth ◽  
Crystal Morphology ◽  
Magnesium Carbonate ◽  
Organic Additives ◽  
X Ray Diffraction ◽  
Morphological Transformation ◽  
X Ray ◽  
Carbonation Process

AbstractVarious morphologies of magnesium carbonate hydrate had been synthesized without using any organic additives by carefully adjusting the reaction temperature and time during the talc carbonation process. At lower temperatures, magnesium carbonate hydrate was prone to display needle-like morphology. With the further increase of the carbonation temperature, the sheet-like crystallites became the preferred morphology, and at higher aging temperatures, these crystallites tended to assemble into layer-like structures with diverse morphologies, such as rose-like particles and nest-like structure. The reaction time had no effect on the crystal morphology, but it affected the particle size and situation of the crystal growth. X-Ray diffraction results showed that these various morphologies were closely related to their crystal structure and compositions. The needle-like magnesium carbonate hydrate had a formula of MgCO3·3H2O, whereas with the morphological transformation from needle-like to sheet-like, rose-like, and nest-like structure, their corresponding compositions also changed from MgCO3·3H2O to 4MgCO3·Mg(OH)2·8H2O, 4MgCO3·Mg(OH)2·5H2O, and 4MgCO3·Mg(OH)2·4H2O.

Characterization of Cold Sprayed Copper Coatings on Al Alloy Substrate

2015 ◽  
Vol 3 (2) ◽  
pp. 41-53
Author(s):  
Tarun Goyal ◽  
T. S. Sidhu ◽  
R. S. Walia
Keyword(s):  
Spray Deposition ◽  
Structural Characteristics ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Coatings ◽  
Powder Particles ◽  
Micro Analysis ◽  
Hardness Values

This study reveals the successful low pressure cold spray deposition of near-uniform, defect free and dense copper coatings approximately 700-1900 µm thick, on Al alloy for electro-technical applications. The micro structural characteristics of the deposits have been studied using the combined techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) and electron-probe micro analysis (EPMA). The coatings exhibited characteristic splat-like, layered morphologies due to the deposition of solid powder particles which appeared to have been plastically deformed on impact to the substrate. The developed coatings have a dense (in the range of 3090-5015 kg/m3)and nearly uniform microstructure, with almost uniform hardness values in the range of 120 -140 Hv, and electrical conductivity in the range of 23-30 MS/m. EDAX, XRD and EPMA results revealed that the main constituent in the coating is Cu.

Effect of Iron Substitution on Structure and Optical Properties of Nanocrystalline CaTiO3

2008 ◽  
Vol 3 ◽  
pp. 123-128 ◽  
Author(s):  
A. Bandyopadhyay ◽  
S. Mondal ◽  
M. Pal ◽  
Umapada Pal ◽  
M. Pal
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Iron Concentration ◽  
Rietveld Analysis ◽  
Exothermic Peak ◽  
Optical And Electrical Properties ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
Soft Chemical Route

Nanocrystalline CaTiO3 powders doped with Fe2O3 have been prepared using a soft chemical route. Precipitation of CaTiO3 nanocrystals has been studied by monitoring the exothermic peak in their DSC spectra. The crystal growth temperature of the samples depends on the concentration of iron. Surface morphology, crystal structure, optical and electrical properties of the nanostructures are investigated. X-ray diffraction study shows that the as-prepared powders are amorphous in nature and CaTiO3 phase formation starts at around 500 0C. Rietveld analysis revealed that the particle size of iron substituted CaTiO3 is in nanometer range. Optical bandgap of the nanostructures varies from 4.3 to 3.7 eV for the variation of iron concentration from 0.05 to 0.2 mole %.

Synthesis and sintering of SiC under high pressure and high temperature

1999 ◽  
Vol 14 (3) ◽  
pp. 906-911 ◽  
Author(s):  
S. K. Bhaumik ◽  
C. Divakar ◽  
S. Usha Devi ◽  
A. K. Singh
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
High Pressure ◽  
Silicon Powder ◽  
Synthesis Temperature ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microscopic Studies ◽  
Simultaneous Synthesis

Starting from elemental powders, simultaneous synthesis and compaction of SiC were conducted at 3 GPa pressure and temperatures in the range 2100–2900 K. The sintered compacts were characterized by x-ray diffraction, microhardness measurements, and microscopic studies. The efficiency of formation of SiC was dependent on the particle size of the silicon powder, crystallinity of the reactant carbon, molar ratio of silicon and carbon, and synthesis temperature and time. Carbon in excess of the stoichiometric amount was required to obtain compacts free from residual silicon. The SiC samples, with a Si: C molar ratio 1: 1.05, prepared at 2100 K for 300 s had a density and hardness of 3.21 g/cm3 (98.8% of theoretical density) and 22 GPa, respectively. The crystal structure of the SiC depended on the synthesis temperature. Pure β–SiC in the temperature range 2100–2500 K, and a mixture of α– and β–SiC above 2500 K were obtained. The β–SiC was highly crystalline and nearly defect-free.

scholarly journals Mechanical alloying of iron-coated NbC and Si in stirred media mill

2019 ◽  
Vol 55 (2) ◽  
pp. 209-216 ◽  
Author(s):  
A. Al-Azzawi ◽  
F. Kristály ◽  
Á. Rácz ◽  
P. Baumli ◽  
K. Bohács ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Mechanical Alloying ◽  
Structural Changes ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Batch Type ◽  
Stress Energy ◽  
Stirred Media Mill

In the current research, the effect of mechanical alloying (MA) of iron-coated NbC and Si on the material?s fineness and crystal structure was investigated. The MA experiments were carried out in a batch-type laboratory scale stirred media mill for various residence times up to 240 min in isopropanol. During MA, milling energy was measured, and stress energy (SE) was calculated. Morphology and material structural changes, during the mechanical alloying process, were determined by means of scanning electron microscopy (SEM) and powder X-ray diffraction (XRD), respectively. The particle size distribution of the product was measured by a Horiba 950 LA laser particle size analyser. Evolution of phases during highenergy milling of NbC, Al-Fe-carbide, Fe, and Si was studied as a function of specific milling energy. Transformations in the crystal structure were revealed, namely the generation of cementite and Nb-Si-carbide, which was proved by XRD results and thermodynamic calculations. As result of the experiments, optimum MA conditions were determined. The application of the mechanical alloying method gives the opportunity to produce nanocrystalline phase from the initial ironcoated NbC and Si powder

scholarly journals Correlation between morphology and magnetic properties of electrochemically produced cobalt powder particles

2015 ◽  
Vol 80 (2) ◽  
pp. 197-207 ◽  
Author(s):  
Vesna Maksimovic ◽  
Nebojsa Nikolic ◽  
Vladan Kusigerski ◽  
Jovan Blanusa
Keyword(s):  
Magnetic Properties ◽  
Cobalt Powder ◽  
Squid Magnetometry ◽  
Parallel Reaction ◽  
X Ray Diffraction ◽  
Applied Current ◽  
X Ray ◽  
Eds Analysis ◽  
Powder Particles ◽  
Current Densities

Cobalt 3D powder particles were successfully prepared by the galvanostatic electrodeposition. Electrodeposited cobalt powder were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Energy Dispersive Spectroscopy (EDS) analysis and SQUID magnetometry. It has been shown that morphology, structure and magnetic properties of cobalt particles are closely associated and can be easily controlled by adjusting process parameters of electrodeposition. Morphology of cobalt powder particles is strongly affected by hydrogen evolution reaction as a parallel reaction to cobalt electrodeposition. Depending on the applied current density, the two types of powder particles were formed: dendrites at lower and spongy-like particles at higher current densities. Morphologies and structures of powder particles are correlated with their magnetic properties, and compared with those of the bulk cobalt. In comparison with the properties of bulk cobalt, the obtained 3D structures exhibited a decreased saturation magnetization (MS), but an enhanced coercivity (HC) which is explained by their peculiar morphology.

Particle Size Distribution and Structural State Analysis of Mechanically Milled Strontium Hexaferrite

2019 ◽  
Vol 946 ◽  
pp. 293-297 ◽  
Author(s):  
Ivan N. Egorov ◽  
Svetlana I. Egorova ◽  
Viktor P. Kryzhanovsky
Keyword(s):  
Particle Size ◽  
Magnetic Fields ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Milling Process ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles

Article presents an experimental study result of milling coarse strontium hexaferrite in beater mill with formation of magneto fluidized bed and without it. Magneto fluidized bed is formed by mutually perpendicular constant and alternating gradient magnetic fields. We studied the dynamics of particle size distribution from milling time and parameters of magnetic fields. Microstructure dynamics of strontium hexaferrite powder particles milled in various regimes was studied by X-ray diffraction methods. Milling efficiency and energy efficiency of milling process were studied in conditions with and without powder fluidization by magnetic fields. Analysis of experimental data showed advantages of milling in magneto fluidized bed in increased efficiency, particle size distribution homogeneity and powder chemical activity because of lattice micro-stresses.

scholarly journals Characterization of Powder Obtained from Surface of Waste-Plastic Bricks

2020 ◽  
Vol 5 (4) ◽  
pp. 462-468
Author(s):  
Rutticka Kedare
Keyword(s):  
Particle Size ◽  
Fine Powder ◽  
X Ray Diffraction ◽  
Waste Plastic ◽  
X Ray ◽  
Plastic Bags ◽  
Powder Particles ◽  
Physical And Chemical ◽  
Scanning Electron

The basic aim of this work is to perform characterization of the powder obtained from surface of waste plastic brick which in turn provides a base to study the physical and chemical composition of bricks made from waste plastic bags and sand (Plastic bricks). The powder used for characterization was obtained from the surface of waste plastic bricks by scratching the surface of bricks with knife-like stainless-steel instruments. Before characterization, this powder was strained through a double layer strainer (mesh number 325, pore size 44 microns) to obtain fine powder particles. This fine powder was further characterised for determining the particle size, crystallinity percentage, elemental composition and to find functional groups present. The techniques used in characterization of powder includes X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy / Energy Dispersive X-ray Spectroscopy (FESEM/EDS). The results obtained from XRD data analysis showed the particle size to be 9.595 nanometres with a crystallinity percentage of 2.113275 percent. EDS and FTIR results when studied simultaneously showed presence of clay minerals like MgO, SiO2, Al2O3, etc.

An X-Ray Diffraction Study of Compacted Metal Powders

1991 ◽  
Vol 35 (A) ◽  
pp. 607-609
Author(s):  
P. D. Killen ◽  
N. A. Raftery ◽  
D.G. Hay
Keyword(s):  
Particle Size ◽  
Copper Powder ◽  
Metal Powders ◽  
X Ray Diffraction ◽  
Iron Powders ◽  
X Ray ◽  
Electrolytic Copper Powder ◽  
Purity Iron ◽  
Effect Of Particle Size ◽  
High Purity Iron

In this study electrolytic copper powder and atomised high purity iron powders of various size, fractions were consolidated to comparable densities by two very different processes (quasistatic pressing and dynamic, or shook wave, compaction). The resulting pairs of compacts had densities of approximately 0.96 of the theoretical density. These specimens were analysed by X-ray diffraction in order to determine the effect of particle size on the response to compaction.

scholarly journals Study of Surface Morphological, Phytochemical and Structural Characteristics of Rhodium (III) Oxide (Rh2O3) Nanoparticles

2015 ◽  
Vol 1 ◽  
pp. 15-19 ◽  
Author(s):  
A. Heidari ◽  
C. Brown
Keyword(s):  
Particle Size ◽  
Structural Characteristics ◽  
Spherical Shape ◽  
Ultrasonic Waves ◽  
Attenuated Total Reflectance ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
Total Reflectance ◽  
X Ray ◽  
The Mean

In the current research, Rhodium (III) Oxide (Rh2O3) nanoparticles were produced in various sizes using ultrasonic waves and by adding various concentrations of linoleic acid as capping agent. Using X–Ray Diffraction (XRD) methods, phytochemical and structural characteristics of the produced samples were studied and the mean particle size was calculated by Debye – Scherer equation. The phytochemical characteristics of the produced nanoparticles were studied by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR–FTIR). The surface morphology of these structures shows that the Rhodium (III) Oxide (Rh2O3) nanoparticles are formed in a spherical shape.

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