Particle Size Distribution and Structural State Analysis of Mechanically Milled Strontium Hexaferrite

2019 ◽  
Vol 946 ◽  
pp. 293-297 ◽  
Author(s):  
Ivan N. Egorov ◽  
Svetlana I. Egorova ◽  
Viktor P. Kryzhanovsky
Keyword(s):  
Particle Size ◽  
Magnetic Fields ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Milling Process ◽  
Strontium Hexaferrite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles

Article presents an experimental study result of milling coarse strontium hexaferrite in beater mill with formation of magneto fluidized bed and without it. Magneto fluidized bed is formed by mutually perpendicular constant and alternating gradient magnetic fields. We studied the dynamics of particle size distribution from milling time and parameters of magnetic fields. Microstructure dynamics of strontium hexaferrite powder particles milled in various regimes was studied by X-ray diffraction methods. Milling efficiency and energy efficiency of milling process were studied in conditions with and without powder fluidization by magnetic fields. Analysis of experimental data showed advantages of milling in magneto fluidized bed in increased efficiency, particle size distribution homogeneity and powder chemical activity because of lattice micro-stresses.

Synthesis of the Mümetal Magnetic Powders by Mechanical Alloying

2011 ◽  
Vol 672 ◽  
pp. 157-160
Author(s):  
Ionel Chicinaş ◽  
Viorel Pop ◽  
Florin Popa ◽  
Virgiliu Călin Prică ◽  
Traian Florin Marinca ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Mechanical Alloying ◽  
Size Distribution ◽  
Milling Time ◽  
Cast Alloy ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rapid Formation

The formation of quaternary 76Ni17Fe5Cu2Cr (wt. %) alloy by mechanical alloying is investigated. The elemental powders of Ni, Fe, Cu and Cr where milled in argon atmosphere in a planetary ball mill for time up to 20 h. Formation of the alloy was checked by X-ray diffraction studies. It is found that the rapid formation of the alloy lead to the rapid establishment of an equilibrium between the welding and fracture process during milling, leading to a constant particle size distribution over a big range of milling time. The morphology of the powders, studied by scanning electron microscopy (SEM) confirms the rapid increase in size. The particle size distribution and the flowability of the powders are also analyzed as a function of milling time. Enhanced magnetization was found for the milled samples, compared to a cast alloy.

Using Lime Mud Waste from Pulp Mill as an Additive in Brick Clay

2014 ◽  
Vol 608 ◽  
pp. 3-7
Author(s):  
Srichalai Khunton ◽  
Siriphan Nilpairach ◽  
Supin Sangsuk
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Pulp Mill ◽  
Mineralogical Composition ◽  
X Ray Diffraction ◽  
Brick Clay ◽  
X Ray ◽  
Lime Mud ◽  
Firing Shrinkage

Lime mud from a pulp mill was used as an additive in brick clay from the southern part of Thailand. It was mixed with the clay from Cha-Aud district, Nakorn Sithammarat province. The chemical composition of lime mud and the clay was characterised by X-ray fluorescence (XRF), and the mineralogical composition was measured by X-ray diffraction (XRD). The particle size distribution was also measured. The main composition of lime mud is CaO, and Cha-Aud clay consists of SiO2 and Al2O3 as major oxides. The lime mud contains calcite as a major phase when Cha-Aud clay is constituted by quartz, kaolinite, illite and goethite. Particle size distribution of lime mud is in the range of 1-50 μm. After the lime mud was neutralized using hydrochloric acid, it was mixed with Cha-Aud clay at 10 wt%. Samples with and without lime mud were sintered at 700, 800, 900 and 1000°C for 1 hour. The results showed that lime mud can be used as an additive in brick clay. Both types of samples were similar in terms of physical properties when their linear firing shrinkage, water absorption and flexural strength were in the same range.

The Influence of Milling Regimes in Beater Mill on Particle Size Distribution and Structural Characteristics of Strontium Hexaferrite Powder

2018 ◽  
Vol 284 ◽  
pp. 158-162
Author(s):  
I.N. Yegorov ◽  
Nikolay Ya. Egorov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fluidized Bed ◽  
Structural Parameters ◽  
Average Particle Size ◽  
Strontium Hexaferrite ◽  
Average Particle ◽  
Electromagnetic Effect ◽  
Coarse Material

The paper experimentally substantiates effectiveness of method of milling particulate ferromagnetic materials in magneto fluidized bed. Comparative results of particle size distributions and structural parameters of strontium hexaferrite SrFe12O19 powder obtained by milling coarse material in beater mill without electromagnetic effect and in same mill with formation of magneto fluidized bed from mill material are presented. The magneto fluidized bed is formed by constant and alternating gradient magnetic fields with induction lines that are mutually perpendicular and parallel to the plane of rotating beaters. It is shown that application of electromagnetic effect to milling coarse material in beater mill allowed to greatly intensify that process, significantly increase powder quality: increase particle size distribution uniformity and decrease average particle size from 1558.50 μm to 0.56 μm after 120 minutes of processing in the mill. X-ray diffraction analysis showed that milling in beater mill in magneto fluidized bed leads to reduction of coherent-scattering region size, increase of lattice microstrain and dislocation density, making powder more active during sintering process.

The Effects of Surfactants on the Granularity of the HA Powder Synthesized by Mechanochemistry

2009 ◽  
Vol 610-613 ◽  
pp. 1323-1326
Author(s):  
Tao Yu ◽  
Jian Dong Ye ◽  
Ying Jun Wang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fine Particles ◽  
Low Cost ◽  
Sodium Hexametaphosphate ◽  
X Ray Diffraction ◽  
Laser Scattering ◽  
X Ray ◽  
Batch Sizes

The hydroxyapatite (HA) was synthesized by wet mechanochemical method；the effects of surfactant, such as triethanolamine, polyethylene glycol (200000), sodium hexametaphosphate, polyvinylpyrrolidone (K30), on the particle size distribution of as-prepared HA powder were studied. Results were characterized by means of X-ray diffraction (XRD), Scanning electron microscopy (SEM), Laser Scattering Particle Size Distribution Analyzer. The results show that the addition of surfactants eliminated the agglomeration of the powder and the uniform, fine particles (D10=0.1149μm, D50=0.12551μm, D90=0.1481μm) were obtained with the Triethanolamine (6 wt %) and Sodium hexametaphosphate (4 wt %) respectively. Our work demonstrates applicability of the mechanosynthesis for reproducible and low-cost synthesis of uniform, fine HCA powder in large batch-sizes.

Influence of the Mechanical Alloying Parameters on the Elaboration of Sic/Al Nanocomposite Powders

2011 ◽  
Vol 672 ◽  
pp. 219-222 ◽  
Author(s):  
Claudiu Nicolicescu ◽  
Mariana Ciobanu ◽  
Lucia Leonat
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Mechanical Alloying ◽  
Size Distribution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Disk Speed ◽  
Friction Mode ◽  
Nanocomposite Powders ◽  
Better Than

The paper presents the experimental work regarding the elaboration of some nanocomposite powders with higher SiC content. For the research, three types of mixtures were prepared: 90SiC-10Al, 70SiC-30Al and 60SiC-40Al using mechanical alloying (MA) technique. The MA was carried out in a vario planetary ball mill Pulverisette 4 for 5 hours using different conditions: - the shock mode (the main disk speed 400 rpm and the planets speed -800 rpm); - the friction mode (the main disk speed 400 rpm and the planets speed 800 rpm). The resulting mixtures was investigated by scanning electron microscopie (SEM), X-ray diffraction pattern (RDX), energy dispersive X-ray analysis (EDAX) and particle size distribution. After 5 hours of MA it is observed that the mixture obtained in the friction mode conditions have a homogenous structure and the particle size distribution is better than the particle size distribution of the mixture obtained in the shock mode conditions.

In Vitro Characterization / Degradation of Two Bioglasses Used as Synthetic Alloplasts for Bone Grafting

2008 ◽  
Vol 396-398 ◽  
pp. 23-26
Author(s):  
Maria Elisa Rodrigues Coimbra ◽  
Carlos Nelson Elias ◽  
Paulo Guilherme Coelho
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Rough Surface ◽  
Chemical Engineering ◽  
Sao Paulo ◽  
São Paulo ◽  
X Ray Diffraction ◽  
Similar Composition ◽  
X Ray

The objective of this study was to physico/chemically characterize a commercially available and a newly developed Bioglass and also to evaluate their degradation properties. Materials and Method: Two bioresorbable glasses were utilized, a bioglass synthesized at Chemical Engineering College (University of São Paulo, Lorena, São Paulo) (BG1), and the other bioglass utilized was Biogran (BG2) (3i Implant Innovations, Brazil). Particles size distribution histograms were developed for both materials, and then they were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) before and after immersion in simulated body fluid (SBF) for 30, 60, and 90 days. Results: The particle size distribution showed that the mean particle diameters at 10%, 50%, and 90% of the total volume were 17.65, 66.18, and 114.71 µm for BG1, and 354.54, 437.5, 525.00 µm for BG2. SEM images of BG1 showed that the as-received material had a rough surface and as the time of degradation elapsed, this surface became smooth. The images of BG2 showed that the as-received material also had a rough surface, and after immersion in SBF, the material’s crystalline content/morphology could be observed. The X-ray diffraction recorded that BG1 showed a silica peak, not seen at BG2. FTIR revealed that both bioglasses were of similar composition, except for the CO3-carbonate minor peak, present at the BG2 sample. Conclusions: 1. The particle size distribution showed a polydispersed pattern for both materials. 2. The material suffered degradation, and the decomposition increased as a function of immersion in SBF. 3. Both bioglasses had similar composition.

scholarly journals Hydroxyapatite/iron oxide nanocomposite prepared by high energy ball milling

2019 ◽  
Vol 13 (2) ◽  
pp. 210-217
Author(s):  
Milica Vucinic-Vasic ◽  
Bratislav Antic ◽  
Marko Boskovic ◽  
Aleksandar Antic ◽  
Jovan Blanusa
Keyword(s):  
Particle Size ◽  
Iron Oxide ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Ball

Nanocomposites (HAp/iron oxide), made of hydroxyapatite (HAp) and ferrimagnetic iron oxide, were synthesized by high-energy ball milling a mixture consisting of iron oxide nanoparticles and the starting materials used for the HAp synthesis: calcium hydrogen phosphate anhydrous (CaHPO4), and calcium hydroxide (Ca(OH)2). Two HAp/iron oxide samples with the magnetic phase content of 12 and 30 wt.% were prepared and their microstructure, morphology and magnetic properties were analysed by X-ray diffraction and transmission electron microscopy. Furthermore, the measurement of particle size distribution was performed by laser scattering, and temperature/field dependence on magnetization was determined. X-ray diffraction data confirmed the formation of two-phased samples (HAp and spinel iron oxide) without the presence of any other parasite phase. The shape of particles was nearly spherical in both samples, ranging from only a few to several tens of nanometres in diameter. These particles formed agglomerates with the most common value of the number-based particle size distribution of 380 and 310 nm for the sample with 12 and 30wt.% of iron oxide, respectively. Magnetization data showed that both HAp/iron oxide composites had superparamagnetic behaviour at room temperature.

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