Hydrogen in Metallic Nanostructures

2007 ◽  
Vol 555 ◽  
pp. 327-334 ◽  
Author(s):  
R.A. Andrievski
Keyword(s):  
Physical Properties ◽  
Crystallite Size ◽  
Ball Milling ◽  
High Energy ◽  
Structural Features ◽  
Metallic Nanostructures ◽  
High Energy Ball Milling ◽  
Universal Method ◽  
Characterization Methods ◽  
Energy Ball

Features of hydrogen nanostructure synthesis are described as applied to metals (Mg and Pd) and intermetallics (Mg2Ni, FeTi and LaNi5). Attention is focused on the high-energy ball milling as a universal method for hydrogen nanostructure preparation. The effect of crystallite size, absorption/desorption properties of Pd - H2, Mg2Ni - H2, TiFe - H2 and Mg - H2 systems are characterized in detail. Structural features and some physical properties of nanohydrides studied by different independent characterization methods are considered.

scholarly journals Microstructure refinement and physical properties of Ag-SnO2 based contact materials prepared by high-energy ball milling

2013 ◽  
Vol 45 (2) ◽  
pp. 173-180 ◽  
Author(s):  
V. Cosovic ◽  
M. Pavlovic ◽  
A. Cosovic ◽  
P. Vulic ◽  
M. Premovic ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Physical Properties ◽  
Ball Milling ◽  
Electrical Contact ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Powder Metallurgy Method ◽  
Contact Materials ◽  
Energy Ball ◽  
Electrical Contact Materials

High energy ball milling was used in order to improve dispersion of metal oxide in Ag-SnO2 electrical contact materials. The processed Ag-SnO2 (92:8) and Ag-SnO2In2O3 (87.8:9.30:2.9) powder mixtures were subsequently consolidated to bulk solid pieces by conventional powder metallurgy method. The characterization of the prepared samples included microstructural analysis by XRD and SEM, as well as measurements of physical properties such as density, hardness and electrical conductivity. The results of X-Ray analysis point to reduction of crystallite size after milling of about ten times. Microstructures of sintered Ag-SnO2 and Ag-SnO2 In2O3 materials display very fine dispersion of the oxide components in silver matrix. Somewhat higher uniformity was obtained for Ag-SnO2 In2O3 material which was illustrated by results of SEM analysis and more consistent microhardness values. The obtained values of studied physical properties were found to be in accordance with observed higher dispersion of metal oxide particles and comparable to properties of commercial electrical contact materials of this type.

Synthesis, Characterization, and ECAP Consolidation of Carbon Nanotube Reinforced AA 4032 Nanocrystalline Composites Produced by High Energy Ball Milling

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
M. S. Senthil Saravanan ◽  
S. P. Kumaresh Babu
Keyword(s):  
Carbon Nanotubes ◽  
Crystallite Size ◽  
Ball Milling ◽  
Base Alloy ◽  
Arc Discharge ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Nanocrystalline Powders ◽  
Peak Broadening ◽  
Energy Ball

In the present work, multiwalled carbon nanotubes (MWNTs) were synthesized by electric arc discharge method in open air atmosphere. The synthesized nanotubes were subjected to multistep purification followed by characterization using Raman spectroscopy and transmission electron microscopy (TEM). These carbon nanotubes (CNTs) have inner and outer diameters of the order of 3.5 nm and 16 nm with an aspect ratio of 63. AA 4032 nanocomposites reinforced with MWNTs were produced by high energy ball milling using elemental powder mixtures. X-ray diffraction (XRD) and scanning electron microscope (SEM) studies showed different phases of composite with and without CNTs. The crystallite size and lattice strain were calculated using an anisotropic model of Williamson–Hall peak broadening analysis, which showed in decreased crystallite size with increasing milling time. TEM studies reveal that the MWNTs were uniformly distributed in the matrix. Thermal stability of the nanocrystalline powders was studied using a differential thermal analyzer (DTA). The mechanically alloyed powders were consolidated using a novel method called equal channel angular pressing (ECAP) at room temperature. The consolidated samples were sintered at 480 °C in argon atmosphere for 90 min. ECAP method was investigated as an alternative to conventionally sintered powder composites. CNT addition has shown significant improvement in the hardness of the system, even though the observed density is relatively low compared with a base alloy. Thus, the results show that ECAP enables sufficient shear deformation results in good metallurgical bonds between particles at lower compaction pressures. Hence, it is proven that ECAP can be effectively used as one of the consolidation technique especially for powders that are difficult to consolidate by other means.

Incorporation of carbon nanotubes into polyethylene by high energy ball milling: Morphology and physical properties

2007 ◽  
Vol 45 (5) ◽  
pp. 597-606 ◽  
Author(s):  
Giuliana Gorrasi ◽  
Maria Sarno ◽  
Antonio Di Bartolomeo ◽  
Diana Sannino ◽  
Paolo Ciambelli ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Physical Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball

Preparation of CNT/AlSi10Mg composite powders by high-energy ball milling and their physical properties

2016 ◽  
Vol 23 (3) ◽  
pp. 330-338 ◽  
Author(s):  
Lin-zhi Wang ◽  
Ying Liu ◽  
Wen-hou Wei ◽  
Xu-guang An ◽  
Tao Zhang ◽  
...  
Keyword(s):  
Physical Properties ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Composite Powders ◽  
Energy Ball

High-Energy Ball Milling Conditions in Formation of NiTiCu Shape Memory Alloys

2021 ◽  
pp. 1-7
Author(s):  
Tomasz Goryczka ◽  
Piotr Salwa ◽  
Maciej Zubko
Keyword(s):  
Chemical Composition ◽  
Shape Memory ◽  
Crystallite Size ◽  
Ball Milling ◽  
Average Crystallite Size ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball ◽  
Average Size ◽  
Grinding Time

The properties and the shape memory effect depend, among other things, on chemical composition, as well as the method of shape memory alloy (SMA) production. One of the manufacturing methods that leads to the amorphous/nanocrystalline SMA is high-energy ball milling combined with annealing. Using this technique, an SMA memory alloy, with the nominal chemical composition of Ni25Ti50Cu25, was produced from commercial elemental powders (purity −99.7%). The structure and morphology were characterized (at the various stages of its production) by the use of X-ray diffraction, as well as electron microscopy (both scanning and transmission). Choosing the appropriate grinding time made it possible to produce an NiTiCu alloy with a different crystallite size. Its average size changed from 6.5 nm (after 50 h) to about 2 nm (100 h). Increasing the grinding time up to 140 h resulted in the formation of areas that showed the B19 martensite and the Ti2(Ni,Cu) phase with the average crystallite size of about 6 nm (as milled). After crystallization, the average size increased to 11 nm.

Structural Features of High-Entropy HfTaTiNbZr Alloy Fabricated by High-Energy Ball Milling

2020 ◽  
Vol 61 (4) ◽  
pp. 421-428
Author(s):  
A. S. Sedegov ◽  
V. S. Tsybulin ◽  
K. V. Kuskov ◽  
N. F. Shkodich ◽  
D. O. Moskovskikh
Keyword(s):  
Ball Milling ◽  
High Energy ◽  
Structural Features ◽  
High Energy Ball Milling ◽  
High Entropy ◽  
Energy Ball

On the crystallite size refinement of ZrB2 by high-energy ball-milling in the presence of SiC

2011 ◽  
Vol 31 (13) ◽  
pp. 2407-2414 ◽  
Author(s):  
V. Zamora ◽  
A.L. Ortiz ◽  
F. Guiberteau ◽  
M. Nygren ◽  
L.L. Shaw
Keyword(s):  
Crystallite Size ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Size Refinement ◽  
Energy Ball

High Energy Planetary Ball Milling of SiC Powders

2007 ◽  
Vol 351 ◽  
pp. 7-14 ◽  
Author(s):  
Yu Bai Pan ◽  
Zheng Ren Huang ◽  
Dong Liang Jiang ◽  
Léo Mazerolles ◽  
D. Michel ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Ball Milling ◽  
Average Crystallite Size ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Fine Powders ◽  
Sic Ceramics ◽  
Sem And Tem ◽  
Planetary Ball Milling ◽  
Energy Ball

The effects of high-energy ball milling on SiC powders were studied using a planetary apparatus. Conditions to obtain nanostructured SiC powders with an average crystallite size of 4 nm were determined and powders were characterized by XRD, SEM and TEM analyses. This process was applied to prepare fine powders leading to dense SiC ceramics by sintering at 1900oC for 30 minutes under 30 MPa in argon.

Effect of Pressing Force on the Physical Properties of CaMgTiO3 Ceramic Prepared by HEBM

2014 ◽  
Vol 895 ◽  
pp. 311-314 ◽  
Author(s):  
Nurhashimah Hassim ◽  
Wan Nurulhuda Wan Shamsuri ◽  
Nur Liyana Amiar Rodin ◽  
Rosli Hussin ◽  
Karim Deraman ◽  
...  
Keyword(s):  
Physical Properties ◽  
Ball Milling ◽  
Grain Growth ◽  
Raw Materials ◽  
High Energy ◽  
Sem Analysis ◽  
High Energy Ball Milling ◽  
Particle Sizes ◽  
Milling Method ◽  
Energy Ball

CaMgTiO3 ceramics were synthesized by using the high energy ball-milling method (HEBM) at different pressing forces. The raw materials were ball milled for 20 hours and sintered at 1000°C. Ceramics surfaces morphologies and particle sizes were measured using SEM analysis. Archimedes’ method was adapted to obtain their densities and porosities. It was found that pressing forces influenced both morphologies and particle sizes. As pressing forces increased, the particle sizes decreased as shown in SEM observation. However, the particle sizes increased at 200 kN due to agglomerated grain growth. The densities were almost constant with increasing of pressing forces while porosities were reduced.

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