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.

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.

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.

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.

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

The Influence of High-Energy Ball Milling Parameters on the Traditional W-Type Ba-Hexaferrite Properties

2008 ◽  
Vol 589 ◽  
pp. 397-402
Author(s):  
Gyula Kakuk ◽  
Ágnes Csanády ◽  
István E. Sajó ◽  
Katalin Papp ◽  
Péter Németh ◽  
...  
Keyword(s):  
Ball Milling ◽  
High Energy ◽  
Milling Process ◽  
High Energy Ball Milling ◽  
Main Task ◽  
Milling Parameters ◽  
Sem And Tem ◽  
Crystallite Sizes ◽  
Energy Ball ◽  
Magnetic Features

The main task of our work was to study the influence of high energy ball milling on the process of W-type hexaferrite material production and to compare the structural, morphological and magnetic features of the different manufacturing ways. The products are analyzed mainly by XRD, SEM and TEM methods. It was shown that high energy ball milling can be used to enhance the synthesis of W-type Ba-hexaferrite due to the much smaller crystallite sizes and their larger surfaces that are produced by the milling process and due to the activation of these surfaces.

scholarly journals Insight on the Interplay between Synthesis Conditions and Thermoelectric Properties of α-MgAgSb

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1857 ◽  
Author(s):  
Julia Camut ◽  
Ignacio Barber Rodriguez ◽  
Hasbuna Kamila ◽  
Aidan Cowley ◽  
Reinhard Sottong ◽  
...  
Keyword(s):  
Ball Milling ◽  
Thermoelectric Properties ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Superior Performance ◽  
Strong Impact ◽  
Secondary Phases ◽  
Synthesis Conditions ◽  
Planetary Ball Milling ◽  
Energy Ball

α-MgAgSb is a very promising thermoelectric material with excellent thermoelectric properties between room temperature and 300 °C, a range where few other thermoelectric materials show good performance. Previous reports rely on a two-step ball-milling process and/or time-consuming annealing. Aiming for a faster and scalable fabrication route, herein, we investigated other potential synthesis routes and their impact on the thermoelectric properties of α-MgAgSb. We started from a gas-atomized MgAg precursor and employed ball-milling only in the final mixing step. Direct comparison of high energy ball-milling and planetary ball-milling revealed that high energy ball milling already induced formation of MgAgSb, while planetary ball milling did not. This had a strong impact on the microstructure and secondary phase fraction, resulting in superior performance of the high energy ball milling route with an attractive average thermoelectric figure of merit of z T avg = 0.9. We also show that the formation of undesired secondary phases cannot be avoided by a modification of the sintering temperature after planetary ball milling, and discuss the influence of commonly observed secondary phases on the carrier mobility and on the thermoelectric properties of α-MgAgSb.

Crystallite Size Refinement of ZrB2by High-Energy Ball Milling

2009 ◽  
Vol 92 (12) ◽  
pp. 3114-3117 ◽  
Author(s):  
Carlos A. Galán ◽  
Angel L. Ortiz ◽  
Fernando Guiberteau ◽  
Leon L. Shaw
Keyword(s):  
Crystallite Size ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Size Refinement ◽  
Energy Ball

Enhancement in Thermoelectric Figure-of-merit of n-type Si-Ge Alloy Synthesized Employing High Energy Ball Milling and Spark Plasma Sintering

2013 ◽  
Vol 1490 ◽  
pp. 51-56 ◽  
Author(s):  
Sivaiah Bathula ◽  
M. Jayasimhadri ◽  
Ajay Dhar ◽  
M. Saravanan ◽  
D. K. Misra ◽  
...  
Keyword(s):  
Crystallite Size ◽  
Ball Milling ◽  
Spark Plasma Sintering ◽  
Figure Of Merit ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Sintered Alloy ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Energy Ball

ABSTRACTIn the present study, we report the enhancement in figure-of-merit (ZT) of nanostructured n-type Silicon-Germanium (Si80Ge20) thermoelectric alloy synthesized using high energy ball milling followed by spark plasma sintering (SPS). After 90 h of ball milling of elemental powders of Si, Ge and P (2 at.%), a complete dissolution of Ge in Si matrix has been observed forming the nanostructured n-type Si80Ge20 alloy powder. X-ray diffraction analysis (XRD) confirmed the crystallite size of the host matrix (Si) to be ∼7 nm and also indicated the formation of an additional phase of SiP nano-precipitates after SPS. HR-TEM analysis revealed that the nano-grained network was retained post-sintering with a crystallite size of size of 9 nm and also confirmed the SiP precipitates formation with a size of 4 to 6 nm. As a result, a very low thermal conductivity of ∼2.3W/mK at 900°C has been observed for Si80Ge20 alloy primarily due to scattering of phonons by nanostructured grains and nano-scaled SiP precipitates which further contribute to this scattering mechanism. Electrical conductivity values of SiGe sintered alloy are slightly lower to that of reported values in literature. This was attributed to the formation of SiP which creates a compositional difference between the grain boundary region and the grain region, leading to a chemical potential difference at interface and the grain region. Figure-of-merit (ZT) of n-type Si80Ge20 nanostructured alloy was found to be ≈1.5 at 900°C, which is the highest reported so far at this temperature.

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