Study on Surface Nanocrystallization of TiAl Alloys Induced by HEBMT

2012 ◽  
Vol 184-185 ◽  
pp. 1250-1254
Author(s):  
Tian Hang Yao ◽  
Wei Zhang ◽  
Yong Liu ◽  
Ming Yang Zhang ◽  
Di Ni Wang
Keyword(s):  
Surface Hardness ◽  
Sample Surface ◽  
High Energy ◽  
X Ray Diffraction ◽  
Tial Alloys ◽  
X Ray ◽  
Depth Direction ◽  
Energy Ball ◽  
Nanocrystalline Layer ◽  
Microscopy Techniques

Utilize the high-energy ball milling techniques (HEBMT) to get a certain thickness of the nanocrystalline layer in gradient structure on TiAl-based alloys surface, while using X-ray diffraction and electron microscopy techniques to analyze the microscopic structure of the surface and study its variation along the depth direction. The results show that through HEBMT, the sample surface can get nanocrystallization and its nano-grain size can be refined to less than 10nm while having a 15μm nanocrystalline layer. Nanoindentation tests show that the surface hardness of the samples after HEBMT can be significantly increased from 340HV to 922HV.

scholarly journals Influence of additional compounds on coercivity of sintered Nd-Fe-B magnets

2018 ◽  
Vol 185 ◽  
pp. 04031
Author(s):  
Thanh Pham ◽  
Duong Nguyen ◽  
Yen Nguyen ◽  
Lam Nguyen ◽  
Quang Dinh ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Energy ◽  
X Ray Diffraction ◽  
Vacuum Sintering ◽  
Melting Method ◽  
X Ray ◽  
Arc Melting ◽  
Milling Method ◽  
Energy Ball ◽  
Microscopy Techniques

In this paper, we investigated the influence of additional compounds of Dy-Nb-Al, Nd-Cu-Al… on the coercivity of the sintered Nd16.5Fe77B6.5 magnets. The additional compounds were first prepared by arc-melting method and then ground into particles with size in the range of 40 - 80 nm using a high energy ball milling method. After that, the additional powder were mixed with micrometer Nd-Fe-B powder before magnetic anisotropic pressing, vacuum sintering and annealing. The structure of the magnets was thoroughly analyzed using X-ray diffraction and electron microscopy techniques. The magnetic properties of the magnets were investigated on a pulsed field magnetometer. The results show that the coercivity of the sintered Nd-Fe-B magnets can be improved by introducing additional nanoparticles to their grain boundaries. The improvement of the coercivity of the magnets is clearly dependent on composition and fraction of the additional compounds. The coercivity has been enhanced 40% for the magnets by adding 3 wt% of the Dy-free compound of Nd40Cu30Al30.

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

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.

Variation of Tungsten Oxide Reduction Mode Using Different High Energy Milling Conditions

2012 ◽  
Vol 727-728 ◽  
pp. 206-209
Author(s):  
Osvaldo Mitsuyuki Cintho ◽  
H.I. Tsai ◽  
M. Bär ◽  
M. de Castro ◽  
E.F. Monlevade ◽  
...  
Keyword(s):  
Tungsten Oxide ◽  
Milling Time ◽  
Xrd Analysis ◽  
High Energy ◽  
Oxide Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Ball ◽  
Fast Increase ◽  
Stoichiometric Proportion

High energy ball milling has been used like alternative route for processing of materials. In the present paper, the reduction of tungsten oxide by aluminum in order to obtain metallic tungsten was studied using a SPEX type high energy mill. A powdered mixture of WO3and metallic aluminum, weighed according to the stoichiometric proportion with an excess 10% Al, was processed with hardened steel utensils using a 1:6 powder-to-ball ratio. The processing was carried out with milling jar temperature measurement in order to detect the reaction type. The temperature evaluation indicated the self-propagating reaction occurrence by fast increase of the jar temperature after a short milling time. The tungsten oxide reduction was verified by X-Ray Diffraction (XRD) analysis and the milling products were characterized by Scanning Electron Microscopy (SEM). The results were slightly different from the literature due to the mill type and milling parameters used in the work.

scholarly journals Composition versus Wear Behaviour of Air Plasma Sprayed NiCr–TiB2–ZrB2 Composite Coating

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 273
Author(s):  
Ning Zhang ◽  
Nannan Zhang ◽  
Sheng Guan ◽  
Shumei Li ◽  
Guangwei Zhang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
High Hardness ◽  
High Energy ◽  
Wear Behaviour ◽  
Air Plasma ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Ball ◽  
Plasma Sprayed

The NiCr–TiB2–ZrB2 composite coating was deposited on the surface of blades made of steel (SUS304) using high-energy ball milling technology and air plasma spraying technology, which aimed to relieve the wear of the blades during operation. The influence of titanium diboride (TiB2) and zirconium diboride (ZrB2) on the microstructure and wear resistance of the coatings was investigated by X-ray diffraction, scanning electron microscopy, Vickers microhardness tester, and a wear tester. The results showed that the TiB2 and ZrB2 particles were unevenly distributed in the coatings and significantly increased the hardness and anti-wear, which contributed to their ultra-high hardness and extremely strong ability to resist deformation. The performance of the coatings was improved with the increase of the number of ceramic phases, while the hardness and wear resistance of the coating could reach their highest value when the TiB2 and ZrB2 respectively took up 15 wt.% of the total mass of the powder.

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.

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.

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.

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