Production of Powders by the Method of Electrospark Dispersion

2016 ◽  
Vol 685 ◽  
pp. 710-714 ◽  
Author(s):  
Sergey P. Zhuravkov ◽  
J.I. Kornev ◽  
Aleksander S. Ivashutenko ◽  
Nikita V. Martyushev

This article is devoted to the research of powders for the additive technologies made by EOS Company. Their analysis showed that the powders’ average diameter is about 30 microns. Powders are received by method of electrospark dispersion. The X-ray diffraction and metallographic analysis of these powders is presented.

2011 ◽  
Vol 306-307 ◽  
pp. 410-415
Author(s):  
Li Sun ◽  
Fu Tian Liu ◽  
Qi Hui Jiang ◽  
Xiu Xiu Chen ◽  
Ping Yang

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO4ž7H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO4ž7H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.


2014 ◽  
Vol 609-610 ◽  
pp. 250-254
Author(s):  
Ya Bin Li ◽  
Jin Tian Huang ◽  
Yan Fei Pan

In the paper, the TiO2nanomaterials adopted the microcrystalline cellulose as the template by the template method and sol-gel method was prepared. Through the infrared spectrometer (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD), the surface morphology, composition and the type of the samples were characterized respectively. The influence of the macro morphology of TiO2photocatalytic performance to use the reaction of decolorization and degradation of methyl orange as model was analyzed. The results showed that TiO2which was produced by the template of sallix fiber was Rod-shaped and the average diameter size of nanocomposite structure was 20.592 nm, which can provide a new method of producing other morphology of TiO2.


MRS Advances ◽  
2019 ◽  
Vol 4 (5-6) ◽  
pp. 277-284
Author(s):  
Nikolay A. Bert ◽  
Vladimir V. Chaldyshev ◽  
Nikolay A. Cherkashin ◽  
Vladimir N. Nevedomskiy ◽  
Valery V. Preobrazhenskii ◽  
...  

ABSTRACTWe studied the microstructure of Al0.28Ga0.72As0.972Sb0.028 metamaterials containing a developed array of AsSb nanoinclusions. The AlGaAsSb films were grown by low-temperature molecular-beam epitaxy followed by high-temperature annealing at 750°C. The process resulted in an array of self-organized AsSb nanonclusions with an average diameter of 15 nm. The volume filling factor was about 0.003. Using transmission electron microscopy and x-ray diffraction we showed that the nanoinclusions have A7-type rhombohedral atomic structure with the following orientation in the matrix (0003)p || {111}m and [-2110]p || 〈220〉m, where p and m indices indicate the AsSb precipitate and AlGaAsSb matrix, correspondingly. The nanoinclusions appeared to be strongly enriched by antimony (more than 90 atomic %), whereas the Sb content in the AlGaAsSb matrix was 2.8 atomic %. The strong enrichment of the inclusion with Sb resulted from the local thermodynamic equilibrium between the solid AlGaAsSb matrix and AsSb inclusions which became liquid at a formation temperature of 750°C.


2018 ◽  
Vol 279 ◽  
pp. 35-43 ◽  
Author(s):  
Ze Chao Jiang ◽  
Fan Yang ◽  
Jian Lan ◽  
Qing Chao Tian ◽  
Wei Dong Xuan ◽  
...  

Preparation of Mn-Cu based damping alloy ingots coupled with strong magnetic fields shows many interesting phenomena on the solidification microstructure and the crystal lattice. In this study, modified M2052 ingots were prepared under different magnetic fields to investigate the bulk solidification behavior by using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Metallographic analysis reveals that the deflection angle of the primary dendrite arm increases with the increase of magnetic field strength. The distribution of chemical composition characterized by X-ray Fluorescence discloses that Mn is enriched while Cu is depleted along the circumferential surface side, and the variation tendency changes from almost a level to a sloping line under applied magnetic field. High magnetic field have altered the orientation of the γ-Mn dendrites from (200) to (111), and the coupling mechanism of alloy solidification with strong magnetic field is discussed based on the experimental results.


2012 ◽  
Vol 268-270 ◽  
pp. 580-583 ◽  
Author(s):  
Yong Tang Jia ◽  
Cui Wu ◽  
Feng Chun Dong ◽  
Gang Huang ◽  
Xian Hua Zeng

The composite nanofiber membranes of poly (ε-caprolactone)/poly(vinyl pyrrolidone) (PCL/PVP) containing silver nanoparticles were prepared by electrospinning method. The morphology of composite nanofibers was characterized by scanning electron microscopy (SEM). The silver nanoparticles on the electrospun fibers were characterized by X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The contact angle and water uptake of PCL/PVP/Ag nanofiber membranes were measured. The SEM photos indicated that the average diameter of the fibers was significantly decreased with the addition of silver nanoparticles. The X-Ray images showed that Ag nanoparticles were distributed on the surface of nanofiber membranes. When the PVP mole ratio was higher than 15%, the nanofiber membranes showed good hydrophilic property. The PCL/PVP/Ag nanofiber membranes could be applied to prepare wound dressing.


2016 ◽  
Vol 16 (4) ◽  
pp. 4029-4034 ◽  
Author(s):  
Chunxia Liu ◽  
Lixia Yang ◽  
Dan Yue ◽  
Mengnan Wang ◽  
Lin Jin ◽  
...  

Rare earth ions (Tb3+, Eu3+) doped CaWO4 microstructures were synthesized by a facile hydrothermal route without using any templates and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectrum. The results indicate that the asprepared samples are well crystallized with scheelite structure of CaWO4, and the average diameter of the microstructures is 2∼4 μm. The morphology of CaWO4:Eu3+ microstructures can be controllably changed from microspheres to microflowers through altering the doping concentration of Eu3+ from 3% to 35%, and the microflowers are constructed by a number of CaWO4:Eu3+ nanoflakes. Under the excitation of UV light, the emission spectrum of CaWO4:Eu3+ is composed of the characteristics emission of Eu3+ 5D0-7FJ (J = 1, 2, 3, 4) transitions, and that of CaWO4:Tb3+ is composed of Tb3+ 5D4-7FJ (J = 6, 5, 4, 3) transitions. Both of the optimal doping concentrations of Tb3+ and Eu3+ in CaWO4 microstructures are about 5%.


1957 ◽  
Vol 1 ◽  
pp. 39-58
Author(s):  
Ralph H. Hiltz ◽  
Stanley L. Lopata

AbstractIn view of present difficulties encountered in met alio graphic methods of phase analysis of titanium and its alloys, the possibility of utilizing integrated X-ray intensities for phase analysis was investigated. Power Formula variables were calculated for titanium, and relative areas of three alpha and one beta peak were determined. Recorded X-ray intensities were obtained from a large number of titanium specimens. The recorded intensities were analyzed and the results compared with those from metallographic analysis. The errors in the method arising from the nature of titanium, texture and peak overlapping, were studied and where possible, compensated for by adjusting the method of measurement and calculation.


2011 ◽  
Vol 364 ◽  
pp. 317-321 ◽  
Author(s):  
Siti Zulaiha Hairaldin ◽  
Wan Md Zin Wan Yunus ◽  
Nor Azowa Ibrahim

In this study, Octadecylamine Modified montmorillonites (ODAMMT) were used to prepare polylactide/polycaprolactone (PLA/PCL) clay nanocomposites. PLA and PCL were blend using an internal mixer by melt blending method. The other sample was blend with natrium monmorillonite (NaMMT) and Octadecylamine modified monmorillonite to produce PLA/PCL-NaMMT and PLA/PCL-ODAMMT. To characterize the polymer nanocomposite, X-ray diffraction (XRD), FTIR and SEM analysis were conducted. Comparison of morphology were made up between neat PLA/PCL, PLA/PCL with presence of of montmorillonite and octadecylamine modified monmorillonite respectively based on SEM micrograph. The number-average diameter was calculated for PLA/PCL, PLA/PCL-NaMMT, and PLA/PCL-ODAMMT.


2010 ◽  
Vol 25 (10) ◽  
pp. 2035-2041 ◽  
Author(s):  
Zhiguo Xia ◽  
Peng Du

CaF2:Yb3+,Er3+ upconversion (UC) luminescence nanoparticles have been synthesized using mesoporous silica (SBA-15) as a hard template. The samples were characterized by x-ray diffraction, Fourier transform infrared spectra, field-emission scanning electron microscopy, transmission electron microscopy, and UC emission spectra, respectively. Highly crystalline cubic phase CaF2:Yb3+,Er3+ nanoparticles are uniformly distributed with an average diameter of about 40–50 nm, and the formation process is also demonstrated. The UC fluorescence has been realized in the as-prepared CaF2:Yb3+,Er3+ nanoparticles on 980-nm excitation. The UC emission transitions for 4F9/2–4I15/2 (red), 2H11/2–4I15/2 (green), 4S3/2–4I15/2 (green), and 2H9/2–4I15/2 (violet) in the Yb3+/Er3+ codoped CaF2 nanoparticles depending on pumping power and temperature have been discussed. The UC mechanism, especially the origin on the temperature-dependent UC emission intensities ratio between 2H11/2 and 4S3/2 levels, have been proposed.


2016 ◽  
Vol 87 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Vincent Mukwaya ◽  
Weidong Yu ◽  
Rabie AM Asad ◽  
Hajo Yagoub

Cellulose nano fibrils (CNFs) were isolated from banana rachis bran using enzyme hydrolysis with subsequent ultra-sonic treatment. The CNFs and bran were characterized by particle size distribution (only the CNFs), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy; the morphology of the banana rachis fiber and CNFs was observed using scanning electron microscopy and transmission electron microscopy, respectively. The furnished nano fibrils had an average diameter of 14.02 ± 2.10 nm and length of 619.6 ± 90.7 nm. The aspect ratio of the CNFs is in the range of long fibrils, that is 44.18. XRD studies revealed that CNFs (48.83%) were more crystalline than the banana bran (27.76%). TGA and derivative thermogravimetry thermograms showed that CNFs were more thermally stable than the bran.


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