Research of the Milling Time Influence on Ag-Cu Powder Particles Size Processed by Mechanical Alloying Route

2012 ◽  
Vol 188 ◽  
pp. 382-387 ◽  
Author(s):  
Oana Gîngu ◽  
Claudiu Nicolicescu ◽  
Gabriela Sima
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Mechanical Alloying ◽  
Size Distribution ◽  
Powder Mixture ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Future Research ◽  
Powder Particles

This research focuses on Ag-Cu powder particles processing by mechanical alloying (MA) route. The powder mixture is representative for the eutectic composition, respectively 72%wt. Ag + 28% wt. Cu. The milling process is developed in high energy ball mill Pulverisette 6, using different size for the milling balls, in wet conditions for 80 hours. One of the most important parameter studied in this research is the particle size distribution of the processed powder mixture. Thus, it changes along the milling time, from 10…75 µm at the beginning of MA process up to (60 – 80) nm at 80 h. The milling parameters will be optimized in future research depending on the particle size distribution related with thermophysical and thermodynamic properties focused on electrical and optical properties improvement.

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.

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.

scholarly journals Effect of Grinding Time on the Particle Size Distribution Characteristics of Tuff Powder

2021 ◽  
pp. X
Author(s):  
Shuhua LIU ◽  
Hao WANG ◽  
Hongling WANG
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Milling Time ◽  
Milling Process ◽  
Coarse Grained ◽  
Distribution Model ◽  
Fine Grained ◽  
Fractal Characteristics ◽  
Grinding Time

We study the grinding dynamic behavior and particle size distribution (PSD) characteristics of tuff powder. With the analysis of particle size and data of activity test, the results indicate that tuff powder is easy to be ground for the coarse-grained while is difficult for the fine-grained. It is feasible to quantitatively express the milling process of tuff powder by Divas-Aliavden milling dynamic equation. The milling speed and the milling time are negatively correlated, and the grinding efficiency is minimized after 60 min. Equivalent particle size (EPS) is positively linearly correlated with the logarithm of grinding time, while specific surface area (SSA) is inversely correlated, both of them have a highly linear correlation. The PSD of tuff powder, which complies well with the Rosin-Rammler-Bennet (RRB) distribution model, has typical fractal characteristics, and its fractal dimension is also positively correlated with the milling time.

Modeling the Production Technology of Fully-Pressed Bi-Metal Powder Materials and Products

2021 ◽  
Vol 316 ◽  
pp. 570-575
Author(s):  
Badrudin G. Gasanov ◽  
Abakar B. Gasanov ◽  
Artem A. Aganov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Bulk Density ◽  
Size Distribution ◽  
Metal Powder ◽  
Production Technology ◽  
Powder Mixture ◽  
Geometric Parameters ◽  
Powder Materials ◽  
Loading Devices

The features of calculating the thickness of the layers of bimetallic powder products without holes and the type of bushings are shown. The effect of the particle size distribution of the powders, the kinematic and geometric parameters of the loading devices and molds on the mechanism of the expiration of the powder mixture and on the thickness of the layers of the molded product is studied. A technique has been developed for determining the dimensions of the feeder cassette and tooling, depending on the overall dimensions and thicknesses of the working layers, in the production of whole-pressed bimetallic products on press machines with a vertical arrangement of layers. It was found that the thickness of each layer of bimetallic products depends on the geometric parameters of the feeder cassette and tooling, bulk density, particle size distribution and other characteristics of the powders, as well as on the speed of lowering the lower punch ν1 .

Observations of the Particle Size Distribution and Concentration in a Coastal System using an In Situ Laser Analyzer

2002 ◽  
Vol 36 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Teresa Serra ◽  
Xavier Casamitjana ◽  
Jordi Colomer ◽  
Timothy C. Granata
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Water Column ◽  
Size Distribution ◽  
Posidonia Oceanica ◽  
High Energy ◽  
Suspended Particles ◽  
Energy Conditions ◽  
Coastal System

An in situ laser particle size analyzer (LISST-100, Sequoia Scientific, Inc.) has been used to study the particle size distribution and concentration of biological and non biological particles in the water column of a Mediterranean coastal system. Two field campaigns have been carried out during low and high energy conditions of the flow, caused by the passage of a storm front. For the low energy period, the water column remained stratified, whereas for the high energetic period the water column was warmer and well mixed. The first study dealt with the distribution of particles near the bottom of the coastal area. Here, two regions were taken into account. The first region was a sea-grass meadow of Posidonia oceanica and the second region was a barren sand area. The second study dealt with the determination of the vertical distribution of suspended particles in the whole water column of the system. The results showed a decrease in the vertical concentration of suspended particles in the water column with the passage of the storm front, which was associated with advection of warm water mass rather than by vertical mixing. In contrast, vertical resuspension determined the fate of suspended particles at the bottom of the water column and an increase of their concentration was found.

Synthesis of Cathode Materials Fe-Doped NiS2 by Mechanical Alloying for Li/NiS2 Cells

2011 ◽  
Vol 287-290 ◽  
pp. 1428-1432
Author(s):  
Xiao Jing Liu ◽  
Dong Wook Park ◽  
Zhe Zhu Xu ◽  
Sang Dae Kang ◽  
In Shup Ahn ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Cathode Materials ◽  
Lithium Ion ◽  
High Energy ◽  
Milling Process ◽  
High Energy Density ◽  
Tetraethylene Glycol ◽  
Wet Milling ◽  
Powder Particles ◽  
Normal Hexane

In order to synthesize the fine compound iron-doped nickel disulfide (NiS2) with environmentally friendly nickel, sulfur and iron powders, mechanical alloying (MA) was conducted for 8 hrs with SPEX Mill at a speed of 1000 rpm. In this process, stearic acid was added as a kind of process control agents (PCAs) to prevent the excessive cold welding. Meanwhile, for the purpose of getting nanocrystalline of Fe-doped NiS2powder particles to improve the contact areas between the active materials, the wet milling process was also done for 30 hrs with normal hexane (C6H14) as a solvent PCA. The prepared powders were characterized by FE-SEM, XRD, EPMA, EDS and TEM. Finally, the charge/discharge properties of Li/Fe-doped NiS2cells were investigated at room temperature by employing 1 M LiCF3SO3(lithium trifluoromethanesulfonate) dissolved in TEGDME (tetraethylene glycol dimethylether) as the electrolyte. The initial discharge capacity of Li/Fe-doped NiS2cell using wet milled powders as the cathode material is 792 mAh/g, which may indicate its high energy density and good future as cathode materials for lithium-ion batteries.

scholarly journals Control of the size and compositional distributions in a milling process by using a reverse breakage matrix approach

2021 ◽  
pp. 4-4
Author(s):  
Nemanja Bojanic ◽  
Aleksandar Fistes ◽  
Tatjana Dosenovic ◽  
Aleksandar Takaci ◽  
Mirjana Brdar ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Milling Process ◽  
Matrix Approach ◽  
Flour Milling ◽  
Input And Output ◽  
Input Material ◽  
Compositional Distribution ◽  
Wheat Flour Milling

A method based on the reverse breakage matrix approach is proposed for controlling the effects that milling has on the particle size distribution and composition of the comminuted material. Applicability, possibilities, and limitations of the proposed method are tested on examples related to the process of wheat flour milling. It has been shown that the reverse matrix approach can be successfully used for defining the particle size distribution of the input material leading to the desired, predetermined particle size and compositional distribution in the output material. Moreover, we have illustrated that it is possible to simultaneously control both, input and output particle size distribution, together with the composition of the output material.

scholarly journals PEMANFAATAN TEKNIK HEM UNTUK PENUMBUHAN CNT DARI GRAFIT MENGGUNAKAN Ni SEBAGAI KATALIS = UTILIZATION OF HEM TECHNIQUE FOR GROWTH OF CNT FROM GRAPHITE POWDERS BY USING Ni AS CATALYST

2016 ◽  
Vol 10 (1) ◽  
pp. 35-40
Author(s):  
Yunasfi . ◽  
P. Purwanto ◽  
Mashadi .
Keyword(s):  
Particle Size ◽  
Raman Spectroscopy ◽  
Electron Microscope ◽  
Carbon Nanotube ◽  
Surface Area ◽  
Transmission Electron Microscope ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Transmission Electron

Utilization of HEM (high energy milling) technique for growth of CNT (carbon nanotube) from graphite powders by using Ni as catalyst was carried out. Milling process performed on a mixture of graphite powder and nickel powder (Ni-C powders) with the ratio of weight percent of 98%: 2%, with a variation of milling time between 25 up to 75 hours. Characterization using PSA (Powder Size Analyzer), SAA (Surface Area Analyzer), TEM (Transmission Electron Microscope) and Raman Spectroscopy performed to obtain information about particle size, surface area, morphology and the structure bonding of the milled powder respectively. The analysis results of Ni-C powders using PSA and SAA showed the smallest particle size and biggest surface area obtained after milling process for 50 hours, i.e. 80 nm and 705 m2/g, respectively. TEM observations revealed formation of flat fibers which quantity increased with increasing milling time. This flattened fiber behave as an initiator for the growth of CNTs. Ni-C powder milling for 50 hours results more clearly show the growth of CNTs. Analysis by Raman Spectroscopy showed two bands at 1582 cm−1 as a peak of G band and at 1350 cm-1 as a peak of D band. These spectra are typical for sp2 structure. The position of G band peak is close to 1600 cm-1 as the evidence of a change to nano-crystalline graphite. The highest intensity of D band shown in the milling process for 50 hours, which indicates that this milling time produces more graphite-like structure compared to other conditions, and is predicted good for growing CNTs. AbstrakPemanfaatan teknik HEM (High Energy Milling) untuk penumbuhan CNT (carbon nanotube) dari serbuk grafit dengan menggunakan Ni sebagai katalis. Proses milling dilakukan terhadap campuran serbuk grafit dan serbuk nikel (serbuk Ni-C) dengan perbandingan berat 98% : 2%, dengan variasi waktu milling antara 25-75 jam. Karakterisasi menggunakan fasilitas PSA (Particle Size Analyzer), SAA (Surface Area Analyzer), dan TEM (Transmission Electron Microscope) serta Raman Spektroscopy yang masing-masingnya untuk mendapatkan informasi tentang ukuran partikel, luas permukaan dan morfologi serta struktur ikatan serbuk hasil milling. Hasil analisis serbuk Ni-C dengan PSA dan SAA menunjukkan ukuran partikel paling kecil dan luas permukaan paling besar diperoleh setelah proses milling selama 50 jam, masing-masing 80 nm dan 705 m2/g. Pengamatan TEM menunjukkan serbuk-serbuk berbentuk serat pipih dengan kuantitas yang meningkat dengan bertambahnya waktu milling. Serat pipih ini perupakan cikal bakal penumbuhan CNT. Serbuk Ni-C hasil milling menunjukkan penumbuhan CNT terlihat lebih jelas setelah milling selama 50 jam. Hasil analisis dengan Raman Spectroscopy memperlihatkan puncak G band pada bilangan gelombang 1582 cm−1 yang merupakan spektrum untuk struktur sp2 dari grafit dan puncak D band pada bilangan gelombang 1350 cm-1 yang mungkin merupakan deformasi struktur grafit. Posisi puncak G band mendekati 1600 cm-1 menjadi bukti perubahan ke grafit nano kristal. Intensitas D band tertinggi ditunjukkan oleh sistem komposit Ni-C hasil proses milling selama 50 jam dan hal ini sebagai indikasi bahwa proses milling selama 50 jam terhadap sistem komposit Ni-C lebih berstruktur mirip grafit (graphitic-like material) dibanding kondisi lainnya dan diprediksi bagus untuk menumbuhkan CNT. Dengan demikian, waktu milling yang optimal untuk penumbuhan CNT dari serbuk grafit dengan menggunakan Ni sebagai katalis adalah adalah 50 jam.  

scholarly journals Microstructure and mechanical behavior of Al-xMg/5Al2O3 nanostructured composites

2022 ◽  
Author(s):  
Mehdi Delshad Chermahini ◽  
Ghorbanali Rafiei Chermahini ◽  
Jamal Safari
Keyword(s):  
Solid Solution ◽  
Grain Size ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Solid Solution Hardening ◽  
Solution Hardening ◽  
Nanostructured Composite ◽  
Powder Particles ◽  
Mg Content

Abstract The effect of Mg content and milling time were investigated on the microstructure and microhardness values of Al-xMg/5Al2O3 (x = 0, 4, 8 and 12 wt %) nanostructured composite prepared via high energy milling technique. XRD results showed an acceleration of alloying process and formation of Al (Mg) ss by enhancing percentage of Mg element. Also, by increase in Mg percentage the grain size reduction was more considerable during milling treatment. Additionally, increment of the Mg content up to 12 wt%, causes the increase in micro-strain of the samples (from 0.31 to 0.82%). Increase in Mg concentration accelerates the mechanical milling process. According to SEM results a coaxial and circular morphology with a uniform distribution of powder particles has been formed. Up to 12 wt% (for each milling time), significant increase in microhardness (215 HV) was carried out due to solid solution hardening and crystallite refinement. From 10 to 15 h, a slight increase in microhardness up to 218 HV can be observed.

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