Preparation and characterization of spherical niobium silicide-based powder particles by electrode induction gas atomization

Physical characterization of a soymilk powder was carried out by electron microscopy. Chemical characterization was analyzed by proximate analysis, mineral composition by atomic absorption spectrometry, fatty acid composition by gas chromatography and protein composition by electrophoresis. The powder consists of large granules of 60—80 μm, which may be hollow, with smaller granules of 10—20 μm attached to them. Powder particles are covered by a layer of fat. During storage at 25 °C fat is spreading over the surface, while at —12 °C the fat is contracting. This change affected chemical stability, resulting in high level of fat oxidation when stored at 4 °C or 25 °C as well as a decrease in unsaturated fatty acids. Storage also affected the chemical properties of the re-constituted soymilk; the pH of a 12% soy powder suspension increased from 6.68±0.05 to 7.06±0.08 after 12 months of storage. Storage temperature did not affect the pH of the suspension and this change could also not be ascribed to protein aggregation.

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Characterization of Cold Sprayed Copper Coatings on Al Alloy Substrate

International Journal of Surface Engineering and Interdisciplinary Materials Science ◽

10.4018/ijseims.2015070103 ◽

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.

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Preparation and Characterization of Al-Si3N4 Composite Particles

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.197.155 ◽

2013 ◽

Vol 197 ◽

pp. 155-161

Author(s):

Daniel Michalik ◽

Nathalie Valle ◽

Jérôme Guillot ◽

Tomasz Pawlik ◽

Malgorzata Sopicka-Lizer ◽

...

Keyword(s):

Silicon Nitride ◽

Opposite Effect ◽

Composite Particles ◽

Mechanochemical Processing ◽

Aluminum Particles ◽

The Core ◽

Transmission Electron ◽

Silicon Nitride Powder ◽

Powder Particles

Fine Al-Si3N4 composite particles were prepared via mechanochemical processing of the coarse aluminum powder and submicron silicon nitride powder in order to obtain the core-shell structure of composite powder particles. It was expected that soft aluminum particles could form a thin coat on hard silicon nitride particles. The resultant particles were characterized through scanning and transmission electron microscopy and electron spectroscopes. Their particle size distribution, specific surface area, nitrogen/oxygen content and phase composition were also determined. Chemical analysis showed that limited oxidation occurred during mechanochemical processing. It has been found that a thin Al-enriched layer (larger than 10 nm) formed at some Si3N4 particles apart from the opposite effect if Si3N4 particles were occluded in coarser Al items. Discussion of the results is also presented.

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Synthesis and Characterization of 3Y-TZP by Gel Solid-State Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.412.61 ◽

2011 ◽

Vol 412 ◽

pp. 61-64

Author(s):

Xiao Bo Wu ◽

Da Zhi Sun ◽

Dan Yu Jiang ◽

Hai Fang Xu ◽

De Xin Huang ◽

...

Keyword(s):

Mechanical Properties ◽

Solid State ◽

Sintering Behavior ◽

X Ray Diffraction ◽

Solid State Method ◽

X Ray ◽

Powder Particles ◽

State Method ◽

Average Size

3Y-TZP powder has been successfully synthesized by gel solid-state method. The structural phases of powder particles were analyzed by X-ray diffraction and the morphology was analyzed by scanning electron microscopy. The average size of grains was 230 nm. The sintering behavior, mechanical properties and microstructure of 3Y-TZP ceramics sintered by this powder were investigated. The experiment results showed that the mechanical properties of ceramics were excellent.

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Features of Amorphization of the Fe-TM-Nd-REM-B Alloys System at Melt Quenching by Gas Atomization

Journal of Metastable and Nanocrystalline Materials ◽

10.4028/www.scientific.net/jmnm.31.51 ◽

2019 ◽

Vol 31 ◽

pp. 51-55

Author(s):

Mikhail Sorokovikov ◽

Valeriy V. Savin ◽

Ludmila A. Savina ◽

V.A. Chaika ◽

I.S. Zherebcov

Keyword(s):

Chemical Composition ◽

Cooling Rate ◽

Primary Crystallization ◽

Primary Phase ◽

Gas Atomization ◽

Spherical Powder ◽

Similar Chemical ◽

Powder Particles ◽

The Moment ◽

Triple Eutectic

Gas atomization powders (GAP) chemical composition which corresponds to the first area of the phase equilibrium, and the fraction that ensures a cooling rate of a separate powder particle of more than 103K/s contains an amorphous component of two types: the first (AC1) has a chemical composition similar to that of the alloy; and the second (AC2) has a chemical composition of the triple eutectic. AC1 is mostly localized on the surface of the powder particles (in the form of layers, shells, nodules) or are detected in the whole volume of the spherical powder particles with its size less than 5 μm. The authors hold that during gas atomization, powder particles of this size have a cooling rate ≥ 105 K/s. Alloys having a similar chemical composition at similar cooling rates are also amorphized by quenching from the liquid state. This proves that an amorphous alloy of the first type is formed directly from a supercooled melt. While AC2 (enriched by Nd) is formed on the border or in the between the crystal phase Fe14Nd2B of the remaining (after primary crystallization during the primary phase) melt enriched by the moment of the solidification of Nd.

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SYNTHESIS AND CHARACTERIZATION OF NANOCRYSTALLINE FeNi AND Ni3Fe ALLOYS

International Journal of Modern Physics B ◽

10.1142/s0217979211058377 ◽

2011 ◽

Vol 25 (07) ◽

pp. 1013-1019 ◽

Cited By ~ 3

Author(s):

S. AZADEHRANJBAR ◽

F. KARIMZADEH ◽

M. H. ENAYATI

Keyword(s):

Ball Mill ◽

Morphological Evolution ◽

Lattice Parameter ◽

Internal Stresses ◽

Alloy Formation ◽

X Ray Diffraction ◽

X Ray ◽

Powder Particles ◽

Fe Alloys

Nanocrystalline FeNi and Ni 3 Fe alloys were prepared by mechanical alloying of Fe and Ni elemental powders using a planetary ball mill under protection atmosphere. X-ray diffraction measurements were performed to follow alloy formation process in these alloys. A heat treatment of 1 h at 800°C was carried out to relax the internal stresses of the milled samples. Morphological evolution of powder particles was revealed by scanning electron microscopy. The value of lattice parameter was reached to 0.35762 nm and the hardness was found to be 686 HV at 30 h milled FeNi powder. In the case of Ni 3 Fe the values of 0.3554 nm and 720 HV were obtained for lattice parameter and hardness, respectively.

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Overspray Powder Characterization of Fe-Based Glassy Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.468 ◽

2012 ◽

Vol 727-728 ◽

pp. 468-475

Author(s):

Conrado Ramos Moreira Afonso ◽

Claudemiro Bolfarini ◽

Walter José Botta Filho ◽

Claudio Shyinti Kiminami

Keyword(s):

Glassy Alloy ◽

Spray Forming ◽

Scanning Calorimetry ◽

Soft Ferromagnetic ◽

Mass Flow Rates ◽

Powder Particles ◽

Glassy Materials ◽

High Cooling Rates ◽

Amorphous Phase Formation

Powder of Fe72Nb4Si10B14 (%at) glassy alloy was obtained by gas atomization in order to investigate the possibilities of amorphous phase formation due to the high cooling rates (103 105 K/s) involved in this process. The ratio between the gas volumetric and the metal mass flow rates used was 1.0, and nitrogen (N2) was used as the atomization gas. The powder, sieved in different granulometric size ranges, was characterized through: X-ray diffratometry (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Fe72Nb4Si10B14 (%at) bulk metallic glass (BMG) showed completely or partially glassy structure depending on the size range. The obtaining of powders with glassy structure that could be applied as shot penning powder particles and thermal spray feeding powder for metallic coatings or would make possible the production of bulk glassy materials by warm consolidation of such powders or even a millimeters thick deposit obtained by spray forming with glassy or metastable microstructure that would be very interesting considering applications as soft ferromagnetic parts.

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