Synthesis and Characterization of Thermo-Sensitive Copper/Paraffin Nanocomposites

2011 ◽  
Vol 55-57 ◽  
pp. 1769-1773
Author(s):  
Bin Xu ◽  
Bai Yang Lou
Keyword(s):  
Cuprous Oxide ◽  
Thermal Sensitivity ◽  
High Energy ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared Spectrometer ◽  
Energy Ball

Thermo-sensitive copper/paraffin nanocomposites were prepared by high energy ball milling. Fourier transform infrared spectrometer (FTIR), x-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to analyze the composition, phase and microstructure of the composites. Furthermore, their thermal sensitivity was investigated. Results reveal that the phase of composites is mainly composed of copper, paraffin and a small amount of cuprous oxide copper. Nanoparticles homogeneously covered by paraffin form the similar core-shell structure. The mass ratio of copper to paraffin has an obvious influence on the thermal sensitivity.

COMPARISON OF ELECTRODE PROPERTIES OF BINARY, TERNARY AND QUATERNARY NANOCRYSTALLINE Mg2Ni-BASED POWDERS

2011 ◽  
Vol 10 (04n05) ◽  
pp. 1067-1071
Author(s):  
MARYAM MOHRI ◽  
SEYED FARSHID KASHANI-BOZORG
Keyword(s):  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Discharge Duration ◽  
Initial Charge ◽  
Energy Ball ◽  
Composite Microstructure ◽  
Ball Milling Technique

The present investigation is focused on the electrode properties of various nanocrystalline Mg2Ni -based powders synthesized using high energy ball milling technique. The chemical composition was modified by the ternary (Nb) and quaternary ( Al and Nb ) additives. The process parameters were adjusted to achieve nanocrystalline based products. Characterization of the ternary and quaternary milled products using scanning and transmission electron microscopy and X-ray diffraction showed a composite microstructure of an amorphous core surrounded by nanocrystalline Mg2Ni . Electrode made from the quaternary milled product showed superior initial charge density and longer discharge duration.

Mechanism of Achieving Nanocrystalline AIRu By Ball Milling

1988 ◽  
Vol 132 ◽  
Author(s):  
E. Hellstern ◽  
H. J. Fecht ◽  
C. Garland ◽  
W. L. Johnson ◽  
W. M. Keck
Keyword(s):  
Ball Milling ◽  
Crystal Size ◽  
Shear Bands ◽  
Nanocrystalline Structure ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Energy Ball ◽  
Small Grains

ABSTRACTWe investigated through X- ray diffraction and transmission electron microscopy the crystal refinement of the intermetallic compound AIRu by high- energy ball milling. The deformation process causes a decrease of crystal size to 5–7 rum and an increase of atomic level strain. This deformation is localized in shear bands with a thickness of 0.5 to 1 micron. Within these bands the crystal lattice breaks into small grains with a typical size of 8–14 rum. Further deformation leads to a final nanocrystalline structure with randomly oriented crystallite grains separated by high- angle grain boundaries.

Mechanosynthesis of La0.95Sr0.05Ga0.90Mg0.10O3-δ

2008 ◽  
Vol 587-588 ◽  
pp. 931-935
Author(s):  
Priscila Gonçalves ◽  
Filipe M. Figueiredo
Keyword(s):  
Perovskite Phase ◽  
Average Crystallite Size ◽  
High Energy ◽  
Equivalent Diameter ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Planetary Rotation ◽  
Transmission Electron ◽  
Size Estimates

The production of La0.95Sr0.05Ga0.90Mg0.10O3-δ powders was achieved at room temperature by a mechanosynthesis route in a high energy planetary ball mill starting from a mixture of lanthanum, strontium, gallium and magnesium oxides. The milling was carried out in nylon containers, using zirconia balls and a balls:powder mass ratio of 10:1. The planetary rotation was kept constant at 650 rotations per minute (rpm), and the container at 1300 rpm, in the opposite direction. The formation of the perovskite phase was detected from the early milling stages and nearly completed after milling for 360 min, as shown by powder X-ray diffraction. Transmission electron microscopy results revealed that powders consist of agglomerates of homogeneous, crystalline particles with an average equivalent diameter of about 16-17 nm, in excellent agreement with average crystallite size estimates obtained from X-ray diffraction.

BBPPAmorphous Si-B-C-N Ceramics Fabricated by High Energy Ball Milling and Hot Pressing

2007 ◽  
Vol 353-358 ◽  
pp. 1505-1508
Author(s):  
Zhi Hua Yang ◽  
Yu Zhou ◽  
De Chang Jia ◽  
Qing Chang Meng ◽  
Chang Qing Yu
Keyword(s):  
Ball Milling ◽  
Hot Pressing ◽  
Hexagonal Boron Nitride ◽  
High Energy ◽  
High Energy Ball Milling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Energy Ball ◽  
Amorphous Si

Amorphous Si-B-C-N ceramics obtained by high energy ball milling and hot pressing using hexagonal boron nitride (h-BN), graphite (C) and amorphous Si as starting materials have been studied. The mechanical milling with high energy resulted in the generation of large amounts of amorphous composites only milled for 5 h. Si-B-C-N powders were consolidation by hot pressing at 1850 °C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) show that small amount of BN and SiC crystal lies in the amorphous matrix. The flexural strength reached the maximal value of 137.2 MPa at a mole ratio of BN/(Si+C) being 0.6.

Characterization of Strontium Ferrites Powders Obtained by High Energy Milling

2005 ◽  
Vol 498-499 ◽  
pp. 311-315
Author(s):  
P.I. Paulin Filho ◽  
R.R. Corrêa
Keyword(s):  
Electron Microscopy ◽  
Barium Carbonate ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Milling ◽  
Transmission Electron ◽  
Strontium Ferrites

Strontium ferrites powders were obtained by high energy milling process after calcinations of iron oxide and barium carbonate. Phase formations and crystallite size was determined using X-ray diffraction. Morphology, particle size and agglomeration stages were analyzed using scanning and transmission electron microscopy. Results show particles in the range of 14 to 40 nanometers, large agglomerates and crystalline phases formation.

Synthesis and Characterization of Luminescent Properties of NaGdF4 Phosphors

2013 ◽  
Vol 423-426 ◽  
pp. 430-434
Author(s):  
Chang Lin Li ◽  
Tian Li ◽  
Jing Liu ◽  
Xin Ze Wang ◽  
Hong Jian Gao ◽  
...  
Keyword(s):  
Solvothermal Method ◽  
Luminescent Properties ◽  
High Energy ◽  
Luminescence Spectra ◽  
Photoluminescence Intensity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Light Excitation ◽  
Energy Ball

β-NaGdF4: Yb, Tm/β-NaGdF4: Eu and β-NaGdF4: Yb, Tm, Eu particles were successfully synthesized by two different methods, solvothermal method and high-energy ball milling. The properties were measured by X-ray diffraction (XRD), TEM and luminescence spectra. All samples shown the strong photoluminescence intensity under 980 nm light excitation and emission of Eu3+ was observed. Finally, two methods are compared in paper.

Microstructural Evolution of Cr-Ta Powder in the Process of Mechanical Alloying

2015 ◽  
Vol 1094 ◽  
pp. 300-304
Author(s):  
Jing Yao ◽  
Shi Qiang Lu ◽  
Xuan Xiao
Keyword(s):  
Mechanical Alloying ◽  
Ball Mill ◽  
Supersaturated Solid Solution ◽  
High Energy ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Ball Mill ◽  
The Hours ◽  
Energy Ball

High energy ball mill tests under the condition of the ball material mass ratio 13:1 and the rotate speed 400 r/min have been employed to investigate the process of mechanical alloying (MA) of Ta and Cr powder mixed in the mole ratio of 1:2.The microstructure evolution process and phase composition were explained useing scanning electron microscope (SEM) and X-ray diffraction (XRD). The results show that, the milled 20h powder existed in Ta (Cr) supersaturated solid solution and amorphous after 40h. Although the hours were spent on ball milling reached to 50h, Laves phase TaCr2had not been made during the process.

Synthesis and Characterization of Copper/Paraffin Nanocomposites for Thermal Actuation

2011 ◽  
Vol 55-57 ◽  
pp. 1764-1768
Author(s):  
Bin Xu ◽  
Bai Yang Lou
Keyword(s):  
Particle Size ◽  
Milling Time ◽  
Thermal Sensitivity ◽  
High Energy ◽  
Transmission Electron ◽  
Thermal Actuation ◽  
Energy Ball ◽  
Thermoforming Process ◽  
Particle Size And Shape

The copper/paraffin nanocomposites were synthesized by high energy ball milling. Observation of the microstructure, comparison and ascertainment of the particle size of the composite were analyzed by transmission electron microscope. Then the composite was put into a home-made copper tube (5 mm in diameter, 20 mm in length, closed at one end) by thermoforming process, and its thermal sensitivity was measured using thermo-controlled optical micro measuring equipment. The effects of milling time on the microstructures and the thermal sensitivity of copper/paraffin nanocomposites were investigated. The results showed that different milling time caused the changes in particle size and shape of the composite, and had a significant effect on its thermal sensitivity. With increasing milling time, the thermal sensitivity of composite gradually increased.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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