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.

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.

Structural changes in titanium dioxide nanocrystals during plastic deformation

2005 ◽  
Vol 38 (5) ◽  
pp. 749-756 ◽  
Author(s):  
Ulrich Gesenhues
Keyword(s):  
Structural Changes ◽  
Crystal Size ◽  
Lower Layer ◽  
High Energy ◽  
Primary Crystal ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hall Method ◽  
Means Of Transmission

The polygonization of 200 nm rutile crystals during dry ball-milling at 10gwas monitored in detail by means of transmission electron microscopy (TEM) and X-ray diffraction (XRD). The TEM results showed how to modify the Williamson–Hall method for a successful evaluation of crystal size and microstrain from XRD profiles. Macrostrain development was determined from the minute shift of the most intense reflection. In addition, changes in pycnometrical density were monitored. Accordingly, the primary crystal is disintegrated during milling into a mosaic of 12–35 nm pieces where the grain boundaries induce up to 1.2% microstrain in a lower layer of 6 nm thickness. Macrostrain in the interior of the crystals rises to 0.03%. The pycnometrical density, reflecting the packing density of atoms in the grain boundary, decreases steadily by 1.1%. The results bear relevance to our understanding of plastic flow and the mechanism of phase transitions of metal oxides during high-energy milling.

Mössbauer, X-ray diffraction and magnetization studies of Fe–Mn–Al–Nb alloys prepared by high energy ball milling

2006 ◽  
Vol 168 (1-3) ◽  
pp. 1057-1063 ◽  
Author(s):  
Ligia E. Zamora ◽  
G. A. Perez Alcazar ◽  
J. M. Greneche ◽  
S. Suriñach
Keyword(s):  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Ball

Microstructural Transformations of an Amorphous Fe90 Zr10 Alloy Induced by High-Energy Ball-Milling

2006 ◽  
Vol 510-511 ◽  
pp. 698-701
Author(s):  
Pyuck Pa Choi ◽  
Young Soon Kwon ◽  
Ji Soon Kim ◽  
Dae Hwan Kwon
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
High Energy ◽  
High Energy Ball Milling ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Melt Spun ◽  
Energy Ball ◽  
Induced Crystallization

Mechanically induced crystallization of an amorphous Fe90Zr10 alloy was studied by means of X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Under high-energy ball-milling in an AGO-2 mill, melt-spun Fe90Zr10 ribbons undergo crystallization into BCC α- Fe(Zr). Zr atoms are found to be solved in the Fe(Zr) grains up to a maximum supersaturation of about 3.5 at.% Zr, where it can be presumed that the remaining Zr atoms are segregated in the grainboundaries. The decomposition degree of the amorphous phase increases with increasing milling time and intensity. It is proposed that the observed crystallization is deformation-induced and rather not attribute to local temperature rises during ball-collisions.

scholarly journals Mechanochemical Reactions of Lithium Niobate Induced by High-Energy Ball-Milling

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 334 ◽  
Author(s):  
Kocsor ◽  
Péter ◽  
Corradi ◽  
Kis ◽  
Gubicza ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Ball Milling ◽  
Coulometric Titration ◽  
High Energy ◽  
Heat Treatments ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reflection Measurement ◽  
Energy Ball ◽  
Mechanochemical Reactions

Lithium niobate (LiNbO3, LN) nanocrystals were prepared by ball-milling of the crucible residue of a Czochralski grown congruent single crystal, using a Spex 8000 Mixer Mill with different types of vials (stainless steel, alumina, tungsten carbide) and various milling parameters. Dynamic light scattering and powder X-ray diffraction were used to determine the achieved particle and grain sizes, respectively. Possible contamination from the vials was checked by energy-dispersive X-ray spectroscopy measurements. Milling resulted in sample darkening due to mechanochemical reduction of Nb (V) via polaron and bipolaron formation, oxygen release and Li2O segregation, while subsequent oxidizing heat-treatments recovered the white color with the evaporation of Li2O and crystallization of a LiNb3O8 phase instead. The phase transformations occurring during both the grinding and the post-grinding heat treatments were studied by Raman spectroscopy, X-ray diffraction and optical reflection measurement, while the Li2O content of the as-ground samples was quantitatively measured by coulometric titration.

Preparation of C/Cu Composite Powders by High-Energy Ball-Milling

2011 ◽  
Vol 319-320 ◽  
pp. 61-63 ◽  
Author(s):  
Xiu Yan Guo ◽  
Guo Jin Ma ◽  
Shi Kun Xie ◽  
Rong Xi Yi ◽  
Zhi Gao
Keyword(s):  
Ball Milling ◽  
Graphite Powder ◽  
High Energy ◽  
Lattice Parameter ◽  
High Energy Ball Milling ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Mixed Powder ◽  
X Ray ◽  
Energy Ball

Cu-4% mixed-powder consisting of rough copper powder and graphite powder was separately mechanical alloyed by high-energy ball milling. The phases and micrograph of these powders were determined by X-ray diffraction and scanning electron microscopy (SEM). The results show an increase in the lattice parameter of copper with milling times, up to a saturation value of about 24h; There was an absence of graphite reflections from X-ray diffractograms after longer milling times.

XANES Analysis of BCC/FCC Two-Phase Binary Alloys

1999 ◽  
Vol 590 ◽  
Author(s):  
P.J. Schilling ◽  
R.C. Tittsworth ◽  
E. Ma ◽  
J.-H. He
Keyword(s):  
Ball Milling ◽  
Binary Alloys ◽  
Critical Factor ◽  
High Energy ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Edge Structure ◽  
X Ray ◽  
Energy Ball ◽  
A New Technique

ABSTRACTA critical factor in the characterization of two-phase binary alloy systems is the determination of the phase fractions and compositions of the two coexisting solid solutions for any given overall composition of the two-phase mixture. In some systems, for example nanocrystalline alloys formed by high-energy ball-milling, these parameters are difficult to attain by traditional techniques like x-ray diffraction. A new technique has been developed to obtain these quantities indirectly from x-ray absorption near edge structure (XANES) data collected at the two relevant absorption edges, with the formulation of this technique presented here in detail. The technique has been tested using Fe-Ni fcc and bcc standards and the results indicate that the method is accurate to within 5%. This method has been applied to two-phase (f.c.c. and b.c.c.) binary alloys formed by ball-milling of Cu100-xFex(x = 50-80).

Microstructure and Anti-Friction Effect of Ball-Milled Expanded Graphite

2013 ◽  
Vol 704 ◽  
pp. 110-113
Author(s):  
Hong Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ball Milling ◽  
Expanded Graphite ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Friction Effect ◽  
Air Atmosphere ◽  
Transmission Electron

Expanded graphite (EG) was ball-milled in a high-energy mill (planetary-type) under an air atmosphere. The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The anti-friction effect of milled EG used as lubricating additive was investigated. After ball-milling, the relatively ordered graphene planes of original EG become deformed, and the d002 spacing becomes broadened. The milled EG used as lubricating additive have an anti-friction effect, and the effect is more marked than that of original EG.

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