Effect of milling treatment and additives on the morphology evolution of α-alumina from a commercial boehmite precursor

2021 ◽  
Vol 76 (2) ◽  
pp. 119-126
Author(s):  
Luoqiang Liu ◽  
Liang Zhang ◽  
Lingling Zhu ◽  
Xing Zhang ◽  
Zexu Gao ◽  
...  
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
Microstructure Evolution ◽  
High Energy ◽  
Experimental Results ◽  
Morphology Evolution ◽  
Morphology Characteristic ◽  
Planetary Ball Milling ◽  
Energy Ball ◽  
Alpha Alumina

Abstract Because calcined alpha alumina (α-Al2O3) inherits the morphology characteristic of milled precursors, it is expected that the α-Al2O3 morphology could be improved by controlling the precursor morphology through the use of different milling processes. The microstructure evolution of the boehmite precursor under different milling treatments (planetary ball milling [PBM] and high-energy ball milling [HEBM]) and its influence on the microstructure of as-synthesized α-Al2O3 were investigated. The experimental results indicate that HEBM has a stronger modification effect in crystallinity, particle size and dispersibility of the boehmite precursor than PBM, which is of great importance to inhibit the formation of the typical worm-like structure of α-Al2O3. The microstructure of α-Al2O3 was further improved by the introduction of NH4BF4, NH4F and NH4Cl as additives. In particular, polygon-like α-Al2O3 particles with a size of 0.5 μm and a good dispersibility were prepared by calcination of the precursor with 30 h of HEBM and 20 wt.% NH4BF4.

Nanostructured Al Powder Obtained by High Energy Ball Milling at Ambient and Cryogenic Temperatures

2014 ◽  
Vol 802 ◽  
pp. 125-129
Author(s):  
Heronilton Mendes de Lira ◽  
Pilar Rey Rodriguez ◽  
Oscar Olimpio de Araújo Filho ◽  
Cezar Henrique Gonzalez ◽  
Severino Leopoldino Urtiga Filho
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
High Performance ◽  
Pure Aluminum ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Nanocrystalline Powders ◽  
Protective Atmosphere ◽  
Energy Ball ◽  
Size And Morphology

High performance nanostructured light metals and alloys are very interesting for replacing conventional heavier materials in many industrial components. High Energy Ball Milling and Cryomilling are useful techniques to obtain nanocrystalline powders. In this work the effect of several milling conditions such as rotation speed, time, ball to powder ratio and temperature on the crystallite and particle size and morphology in pure aluminum are presented. X-Ray Diffraction, Laser Diffraction and Scanning Electron Microscopy are used. High energy ball milling at ambient and cryogenic temperature of Al powders rapidly leads to a nanometer size down to about 35 nm. High ball to powder ratio promotes both low crystallite and particle size. Small crystallite size like 18 nm and particle size as 4 μm were achieved in the most energetic conditions at ambient temperature. Isopropyl alcohol used as liquid media and protective atmosphere has a strong influence on the results depending on the milling temperature of Al.

A Study on Characteristics of TiH2-Al-Nb Alloyed Powder During High Energy Ball Milling

2011 ◽  
Vol 688 ◽  
pp. 1-5
Author(s):  
Hua Chen ◽  
Tian Yu Zhang ◽  
X.Y Lu ◽  
Su Qiu Jia ◽  
Zhi Long Chai
Keyword(s):  
Ball Milling ◽  
Metastable Phase ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Morphology Evolution ◽  
System Alloy ◽  
Forming Process ◽  
Mixed Powder ◽  
Tial Intermetallics ◽  
Energy Ball

In this paper, TiH2-47Al-5Nb (at.%) and TiH2-47Al-7Nb(at.%) alloys were mixed and synthesized using TiH2, Al and Nb powders. The composition and morphology evolution of the mixed powder were systematically investigated during high energy ball milling. The results show obvious that structure change of the particle during milling, and amorphous, TiAl, Ti3Al and Ti2Al phases at nanoscale are formed. The addition of Nb shows an active influence on the decomposition of TiH2and formation of TiAl-intermetallics. Compare with Ti-Al system alloy, the forming process of TiAl-intermetallics for TiH2-Al-Nb system alloy is different and slower. Ti2Al metastable phase formed after ball milling for 15 h in our experiments.

Microstructure evolution and interface structure of Al-40 wt% Si composites produced by high-energy ball milling

2019 ◽  
Vol 35 (4) ◽  
pp. 512-519 ◽  
Author(s):  
Yuanyuan Chen ◽  
Zhangping Hu ◽  
Yifei Xu ◽  
Jiangyong Wang ◽  
Peter Schützendübe ◽  
...  
Keyword(s):  
Ball Milling ◽  
Microstructure Evolution ◽  
High Energy ◽  
Interface Structure ◽  
High Energy Ball Milling ◽  
Energy Ball

Spark Plasma Sintering of High-Energy Ball-Milled ZrB2 and HfB2 Powders with 20vol% SiC

2018 ◽  
Vol 941 ◽  
pp. 1990-1995
Author(s):  
Naidu V. Seetala ◽  
Cyerra L. Prevo ◽  
Lawrence E. Matson ◽  
Thomas S. Key ◽  
Ilseok I. Park
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Ball Milling ◽  
Milling Time ◽  
High Energy ◽  
Micro Hardness ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Energy Ball ◽  
Ball Milling Time

ZrB2 and HfB2 with incorporation of SiC are being considered as structural materials for elevated temperature applications. We used high energy ball milling of micron-size powders to increase lattice distortion enhanced inter-diffusion to get uniform distribution of SiC and reduce grain growth during Spark Plasma Sintering (SPS). High-energy planetary ball milling was performed on ZrB2 or HfB2 with 20vol% SiC powders for 24 and 48 hrs. The particle size distribution and crystal micro-strain were examined using Dynamic Light Scattering Technique and x-ray diffraction (XRD), respectively. XRD spectra were analyzed using Williamson-Hall plots to estimate the crystal micro-strain. The particle size decreased, and the crystal micro-strain increased with the increasing ball milling time. The SPS consolidation was performed at 32 MPa and 2,000°C. The SEM observation showed a tremendous decrease in SiC segregation and a reduction in grain size due to high energy ball milling of the precursor powders. Flexural strength of the SPS consolidated composites were studied using Four-Point Bend Beam test, and the micro-hardness was measured using Vickers micro-indenter with 1,000 gf load. Good correlation is observed in SPS consolidated ZrB2+SiC with increased micro-strain as the ball milling time increased: grain size decreased (from 9.7 to 3.2 μm), flexural strength (from 54 to 426 MPa) and micro-hardness (from 1528 to 1952 VHN) increased. The correlation is less evident in HfB2+SiC composites, especially in micro-hardness which showed a decrease with increasing ball milling time.

High Energy Ball-Milling of Tin Titanate Zirconate for Use in Microwave Applications

2006 ◽  
Vol 45 ◽  
pp. 480-485 ◽  
Author(s):  
V.L. Arantes ◽  
Dulcina P.F. Souza
Keyword(s):  
Particle Size ◽  
Dielectric Properties ◽  
Ball Milling ◽  
High Energy ◽  
Liquid Phase Sintering ◽  
High Energy Ball Milling ◽  
X Ray Diffraction ◽  
Microwave Frequencies ◽  
Particle Size Analyzer ◽  
Energy Ball

Tin titanate zirconate (ZTS) is widely known for its good dielectric properties at high frequencies and has been widely employed as a dielectric resonator. ZTS does not sinter easily by solid state difusion and it is necessary to introduce sintering aids capable of increasing diffusion coefficients and/or leading to liquid phase sintering. Consequently, the dielectric properties in microwave frequencies can be reduced. This work focused on the utilization of high energy ball-milling as a method of reducing initial particle size and further improving sintering of ZTS.The powders obtained were characterized by X-ray diffraction as a function of milling time, as well as by a light scattering particle size analyzer.

Reducing the crystallite and particle size of SrFe12O19 with PVA by high energy ball milling

2019 ◽  
Vol 771 ◽  
pp. 464-470 ◽  
Author(s):  
F.N. Tenorio Gonzalez ◽  
I.R. Barajas Rosales ◽  
P. Vera Serna ◽  
F. Sánchez de Jesus ◽  
A.M. Bolarin Miró ◽  
...  
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball

Mechanochemically synthesized m-BiVO4 nanoparticles for visible light photocatalysis

RSC Advances ◽  
2016 ◽  
Vol 6 (19) ◽  
pp. 15796-15802 ◽  
Author(s):  
Q. Luo ◽  
L. Zhang ◽  
X. Chen ◽  
O. K. Tan ◽  
K. C. Leong
Keyword(s):  
Particle Size ◽  
Visible Light ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Visible Light Photocatalysis ◽  
Energy Ball ◽  
Photocatalytic Applications

Mechanochemical high energy ball milling approach was used to synthesize monoclinic BiVO4 (m-BiVO4) nanoparticles in an attempt to simultaneously reduce the particle size and improve the throughput for practical photocatalytic applications.

Structure and Magnetic Properties of NdFeB Powder Prepared by Hydrogen Decrepitation and High-Energy Ball Milling

2014 ◽  
Vol 604 ◽  
pp. 262-266 ◽  
Author(s):  
Zoryana Mural ◽  
Lauri Kollo ◽  
Rainer Traksmaa ◽  
Kaspar Kallip ◽  
Joosep Link ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Ball Milling ◽  
Magnetic Moments ◽  
Weight Ratio ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Final Particle ◽  
Energy Ball ◽  
Hydrogen Decrepitation

An ingot of NdFeB alloy was disintegrated by hydrogen decrepitation (HD). High-energy ball milling technique with hard metal milling elements and balls was employed to refine HD powders down to particle size optimum for magnet processing. The experiments were performed according to experimental plan to optimize the milling parameters regarding particle size, contamination and magnetic properties of the powder. The effect of milling time, speed of rotation, ball-powder weight ratio (BPR) and amount of wet agent was investigated. The highest influence was shown to be from attritor speed of rotation, ball-to powder ratio and combined effect of milling wet agent and rotating speed. Unified parameter of estimated number of total ball impacts was calculated, which allows predicting the final particle size of the powder at different milling speeds. Magnetic moments of powders were measured.

Particle size evolution of V–4Cr–4Ti powders in high energy vibrating and planetary ball milling

2019 ◽  
Vol 6 (6) ◽  
pp. 066535 ◽  
Author(s):  
Y F Zhang ◽  
R R Li ◽  
X L Zhao ◽  
S Z Diao ◽  
P P Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
High Energy ◽  
Size Evolution ◽  
Planetary Ball Milling
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