Preparation of La0.7Sr0.3Co0.2Fe0.8O3-δ (LSCF 7328) by Combination of Mechanochemical and Solid State Reaction

2017 ◽  
Vol 744 ◽  
pp. 399-403 ◽  
Author(s):  
Silvana Dwi Nurherdiana ◽  
Nikmatin Sholichah ◽  
Rendy Muhamad Iqbal ◽  
Mutya Sandei Sahasrikirana ◽  
Wahyu Prasetyo Utomo ◽  
...  
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
Perovskite Oxide ◽  
Combination Method ◽  
Structure Evolution ◽  
Preparation Methods ◽  
Grinding Method

Structure evolution and morphology of La0.7Sr0.3Co0.8Fe0.2O3-δ (LSCF 7328) were investigated during two different preparation methods namely mechanochemical and combination of mechanochemical-solid state. The result shows that no characteristic peak of perovskite oxide was found on the diffractogram of the product of sole mechanochemical method at 600 rpm and up to 12 h of high energy milling process. On the other hand, the manual grinding method that was followed by solid state calcination produces irregular particle size. Due to the result, the combination of both methods was proposed to obtain the fine structure formation and particle size distribution. Rietveld refinement was used to investigate the lattice distortion. It was found that unit cell remains unchanged at increasing milling time. Moreover, the combination method produces regular particle size at milling time of 0.5 h. At longer milling time, the more regular particle size is formed which comes from highly energy transfer of milling.

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 Recycling Chips of Stainless Steel Using a Full Factorial Design

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 842
Author(s):  
Claudiney Mendonça ◽  
Patricia Capellato ◽  
Emin Bayraktar ◽  
Fábio Gatamorta ◽  
José Gomes ◽  
...  
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Vanadium Carbide ◽  
Milling Time ◽  
Rotation Speed ◽  
Weight Ratio ◽  
High Energy ◽  
Milling Process ◽  
Full Factorial

The aim of this study was to provide an experimental investigation on the novel method for recycling chips of duplex stainless steel, with the addition of vanadium carbide, in order to produce metal/carbide composites from a high-energy mechanical milling process. Powders of duplex stainless steel with the addition of vanadium carbide were prepared by high-energy mechanical ball milling utilizing a planetary ball mill. For this proposal, experiments following a full factorial design with two replicates were planned, performed, and then analyzed. The four factors investigated in this study were rotation speed, milling time, powder to ball weight ratio and carbide percentage. For each factor, the experiments were conducted into two levels so that the internal behavior among them could be statistically estimated: 250 to 350 rpm for rotation speed, 10 to 50 h for milling time, 10:1 to 22:1 for powder to ball weight ratio, and 0 to 3% carbide percentage. In order to measure and characterize particle size, we utilized the analysis of particle size and a scanning electron microscopy. The results showed with the addition of carbide in the milling process cause an average of reduction in particle size when compared with the material without carbide added. All the four factors investigated in this study presented significant influence on the milling process of duplex stainless steel chips and the reduction of particle size. The statistical analysis showed that the addition of carbide in the process is the most influential factor, followed by the milling time, rotation speed and powder to ball weight ratio. Significant interaction effects among these factors were also identified.

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.

Modeling Mechanical Milling Process for Synthesis of Graphite Nanoparticles and their Characterization

2014 ◽  
Vol 922 ◽  
pp. 586-591 ◽  
Author(s):  
Himanshu Panjiar ◽  
R.P. Gakkhar ◽  
B.S.S. Daniel
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Mechanical Milling ◽  
Milling Time ◽  
High Energy ◽  
Milling Process ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Graphite Nanoparticles

The synthesis of graphite nanoparticles at ambient temperature by high energy mechanical milling is modelled using ANN (Artificial Neural Network). The effect of milling time on the evolution of particle size, inclusion, microstructure and morphology were examined using XRD (X-Ray Diffraction), EDS (Energy Dispersive X-Ray Spectroscopy), SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope). ANN was effectively used to predict the influence of milling time on particle size and to forecast the milling time for the formation of nanoparticles. XRD results of investigation revealed change in strain behaviour of graphite particles of different sizes when heat treated.

scholarly journals Solid State Synthesis of CaMnO3 from CaCO3-MnCO3 Mixtures by Mechanical Energy

2006 ◽  
Vol 61 (3) ◽  
pp. 281-286 ◽  
Author(s):  
Vittorio Berbenni ◽  
Chiara Milanese ◽  
Giovanna Bruni ◽  
Pacifico Cofrancesco ◽  
Amedeo Marini
Keyword(s):  
Particle Size ◽  
Solid State ◽  
Mechanical Stress ◽  
Milling Time ◽  
Mechanical Energy ◽  
High Energy ◽  
Solid State Synthesis ◽  
Annealing Conditions ◽  
Calcium Manganite ◽  
Induced Decomposition

Abstract A solid state synthesis of calcium manganite (CaMnO3) is described where equimolecular mixtures CaCO3:MnCO3 have been subjected to mechanical stress (high energy milling) so yielding CaCO3-MnCO3 solid solutions of nanometric particle size. TG measurements have shown that a link exists between milling time, the extent of non-stoichiometry and the milling-induced decomposition of MnCO3 to Mn3O4. A short (2 h) annealing at 850 °C performed on a sample mixture milled for 25 h leads to non-stoichiometric CaMnO3−x. No sure conclusion could be drawn for the stoichiometry of CaMnO3 obtained, under the same annealing conditions, from a mixture milled for longer time (150 h). No synthesis of CaMnO3 could be effected by long (48 h) annealing at 1200 °C of mixtures that had not been subjected to mechanical stress.

scholarly journals The Structural Evolution of Al86Ni9La5 Glassy Ribbons during Milling at Room and Cryogenic Temperatures

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1956
Author(s):  
Zhicheng Yan ◽  
Yan Liu ◽  
Shaopeng Pan ◽  
Yihua Hu ◽  
Jing Pang ◽  
...  
Keyword(s):  
Milling Time ◽  
Shear Bands ◽  
Structural Evolution ◽  
High Energy ◽  
Milling Process ◽  
Cryogenic Temperatures ◽  
Dynamic Simulations ◽  
Tricapped Trigonal Prism ◽  
Medium Range ◽  
Energy Ball

Melt-spun metallic Al86Ni9La5 glassy ribbons solidified at different circumferential speeds (Sc) were subjected to high-energy ball milling at room and cryogenic temperatures. Crystallization induced by milling was found in the Al86Ni9La5 solidified at lower circumferential speed (Sc = 14.7 m/s), while the Al86Ni9La5 with Sc = 36.6 m/s kept amorphous. Besides, a trend of structural rejuvenation during milling process was observed, as the onset temperatures (Tx1, Tx2) and the crystallization enthalpies (ΔH1, ΔH2) first decreased and then increased along with the milling time. We explored the structural origin of crystallization by ab initio molecular dynamic simulations and found that the tricapped trigonal prism (TTP) Ni-centered clusters with a higher frequency in samples solidified at a lower cooling rate, which tend to link into medium-range orders (MROs), may promote crystallization by initiating the shear bands during milling. Based on the deformation mechanism and crush of metallic glasses, we presented a qualitative model to explain the structural rejuvenation during milling.

scholarly journals Electrical Conductivity Behavior of La0.5Ca0.5Mn0.5Fe0.5O3 Synthetized by the Solid State Reaction

2018 ◽  
Vol 12 (12) ◽  
pp. 174
Author(s):  
H. A. Martínez-Rodríguez ◽  
J. F. Jurado ◽  
E. Restrepo-Parra
Keyword(s):  
Solid State ◽  
Thermal Treatment ◽  
Solid State Reaction ◽  
Milling Time ◽  
Electrochemical Impedance ◽  
Solid State Reaction Method ◽  
Milling Process ◽  
Secondary Phases ◽  
Two Samples ◽  
Semiconductor Behavior

La0.5Ca0.5Mn0.5Fe0.5O3 was synthesized using the solid state reaction method. This method consists of two main processes: a milling process and a subsequent thermal treatment. Two samples at different conditions were produced: one using 2 h of milling time and 900°C (M-I), and the other using 6 h of milling time and 1200°C of thermal treatment (M-II).  X-ray diffraction analysis indicated, in both cases, an orthorhombic crystalline ordering of the space group Pbnm. For the case of M-I, the material exhibited secondary phases, different than the desired phase; on the contrary, in M-II, these secondary phases were not present. The dielectric response determined using electrochemical impedance spectroscopy (EIS) performed in a temperature range between 20°C and 300°C exhibited a thermally activated semiconductor behavior with activation energies of Eg= 0.11±0.05 eV and Eg= 0.47±0.06 eV for M-I and M-II, respectively.

Changes in Particle Size and Crystallinity in Ground Nickel Powder

2008 ◽  
Vol 587-588 ◽  
pp. 468-472
Author(s):  
J.M. González ◽  
José A. Rodríguez ◽  
Enrique J. Herrera
Keyword(s):  
Particle Size ◽  
Specific Surface ◽  
Crystallite Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Nickel Powder ◽  
Milling Time ◽  
High Energy ◽  
Published Data ◽  
Average Particle

Nickel powder was dry-milled using a high-energy disc-oscillating mill. The average particle size increases and the specific surface area diminishes with milling time. Crystallite size decreases and microstrains increase, under the same conditions, as shown by X-ray analysis. At 120 min milling time, the crystallite size has a value of 17 nm, i.e., a nanostructured powder, with a perturbed lattice, is obtained. The above results have been compared with published data about the effects of milling on a ceramic powder. There is, in both cases, a general agreement concerning the changes produced in crystallite size. Nevertheless, opposite results are reached regarding particle size and specific surface area.

Improved lithium insertion/extraction properties of single-walled carbon nanotubes by high-energy ball milling

2008 ◽  
Vol 23 (9) ◽  
pp. 2458-2466 ◽  
Author(s):  
JiYong Eom ◽  
HyukSang Kwon
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Single Walled Carbon Nanotubes ◽  
High Energy ◽  
Milling Process ◽  
Extraction Properties ◽  
Energy Ball ◽  
Insertion Sites ◽  
Walled Carbon Nanotubes ◽  
Ball Milling Time

The effects of ball milling on lithium (Li) insertion/extraction properties into/from single-walled carbon nanotubes (SWNTs) were investigated. The SWNTs were synthesized on supported catalysts by thermal chemical-vapor deposition method, purified, and mechanically ball-milled by high-energy ball milling. The purified SWNTs and the ball-milled SWNTs were electrochemically inserted/extracted with Li. The structural and chemical modifications in the ball-milled SWNTs change the insertion/extraction properties of Li ions into/from the ball-milled SWNTs. The reversible capacity (Crev) increases with increase in the ball milling time, from 616 mAh/g (Li1.7C6) for the purified SWNTs to 988 mAh/g (Li2.7C6) for the ball-milled SWNTs. The undesirable irreversible capacity (Cirr) decreases continuously with increase in the ball milling time, from 1573 mAh/g (Li4.2C6) for the purified SWNTs to 845 mAh/g (Li2.3C6) for the ball-milled SWNTs. The enhancedCrevof the ball-milled SWNTs is presumably due to a continuous decrease in theCirrbecause the SWNTs develop a densely packed structure on the ball milling process. The insertion of Li ions into the ball-milled SWNTs is facilitated by various Li insertion sites formed during the ball milling process in spite of small surface area than the purified SWNTs. Lithium ions inserted into various insertion sites enhance theCrevin the ball-milled SWNTs with the large voltage hysteresis by hindrance of the extraction of Li ions from the ball-milled SWNTs. In addition, the ball-milled samples exhibit more stable cycle capacities than the purified samples during the charge/discharge cycling.

scholarly journals Working Volume and Milling Time on the Product Size/Morphology, Product Yield, and Electricity Consumption in the Ball-Milling Process of Organic Material

2018 ◽  
Vol 3 (2) ◽  
pp. 82 ◽  
Author(s):  
Asep Bayu Dani Nandiyanto ◽  
Riezqa Andika ◽  
Muhammad Aziz ◽  
Lala Septem Riza
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
Organic Material ◽  
Milling Time ◽  
Electricity Consumption ◽  
Product Yield ◽  
Milling Process ◽  
Final Particle ◽  
Ball Milling Process ◽  
Working Volume

Analysis of ball-milling process under various conditions (i.e. working volume, milling time, and material load) on the material properties (i.e. chemical composition, as well as particle size and morphology), product yield, and electricity consumption was investigated. Turmeric (curcuma longa) was used as a model of size-reduced organic material due to its thermally and chemically stability, and fragile. Thus, clear examination on the size-reduction phenomenon during the milling process can be done without considering any reaction as well as time-consuming process. Results showed that working volume is prospective to control the characteristics of product. Working volume manages the shear stress and the collision phenomena during the process. Specifically, the lower working volume led to the production of particles with blunt-edged morphology and sizes of several micrometers. Although working volume is potentially used for managing the final particle size, this parameter has a direct impact to the product yield and electricity consumption. Adjustment of the milling time is also important due to its relation to breaking material and electrical consumption.

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