scholarly journals High purity hematite (Fe2O3) from beach sands for soft ferrite magnetic materials application

2021 ◽  
Vol 869 (1) ◽  
pp. 012059
Author(s):  
A Rahwanto ◽  
M N Machmud ◽  
Fauzi ◽  
I Irhamni ◽  
Z Zulfalina ◽  
...  
Keyword(s):  
Direct Reduction ◽  
Magnetic Behavior ◽  
High Energy ◽  
Hydraulic Press ◽  
Raw Material ◽  
Major Phase ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Scherrer Formula ◽  
Hematite Fe2o3

Abstract Actually, the potential and deposites are rich and spread in many place, but the process from raw material to industrial product is not optimal yet. In this work, the manufacture of iron sand was done using direct reduction technique by compact coals as reductor. The carbon compound of coals were using for releasing oxide in magnetite compounds (Fe3O4) of iron sand, so it could be transformed to Fe phase. The iron sand was firstly milled using high energy ball mill (HEBM) for 0, 10, 20, and 40 hours. Then the iron sands samples were mixed with coals, bentonite and compacted using hydraulic press. Then, loaded into furnace and sintered at 700 °C, 800 °C, and 900 °C. As the results, it was identified (using XRF) that the major phase was Fe2O3 (75.40 %). Consistent with XRF results, the phase composition observation by using XRD was shown that the major phase of sample was Fe2O3 (hematite). It was also shown that the crystallite size of the sample was around 8 nm, as calcultaed using Scherrer formula. The magnetic behavior investigation was showed that the decreasing in magnetic saturation value (Ms) and remanent (Br) and followed by increasing the coercivity value (Hc).

Magnetic Properties of Nanocrystalline Fe50Co50 Powders

2003 ◽  
Vol 788 ◽  
Author(s):  
Shashishekar Basavaraju ◽  
Ian Baker
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Magnetic Force ◽  
Milling Time ◽  
Magnetic Behavior ◽  
High Energy ◽  
Soft Magnetic ◽  
Scanning Calorimetry ◽  
High Energy Ball Mill ◽  
Energy Ball

ABSTRACTNanocrystalline stoichiometric FeCo powders were prepared by mechanically alloying elemental Fe and Co powders using a high-energy ball mill. The microstructural evolution was studied as a function of milling time and subsequent annealing using X-ray diffractometry and differential scanning calorimetry. The magnetic behavior of the specimens was characterized using a vibrating sample magnetometer and a magnetic force microscope. A reduction in grain size coupled with an increase in coercivity was observed as function of milling time. The smallest grain size of 4 nm, which exhibited a coercivity of 122 Oe and magnetization of 2 T at room temperature, was obtained after 240 h of milling. The reduction in grain size during milling was not accompanied by enhanced soft magnetic properties.

Characterization and Magnetic Behavior of Fe and Nd−Fe−B Nanoparticles by Surfactant-Capped High-Energy Ball Mill

2006 ◽  
Vol 111 (3) ◽  
pp. 1219-1222 ◽  
Author(s):  
Hyun Gil Cha ◽  
Young Hwan Kim ◽  
Chang Woo Kim ◽  
Hae Woong Kwon ◽  
Young Soo Kang
Keyword(s):  
Ball Mill ◽  
Magnetic Behavior ◽  
High Energy ◽  
High Energy Ball Mill ◽  
Energy Ball

Structural Analysis of PM Biocomposites Based on Hydroxyapatite Nanopowders Elaborated by Spark Plasma Sintering Route

2012 ◽  
Vol 188 ◽  
pp. 52-58
Author(s):  
Bebe Adrian Olei ◽  
Oana Gîngu ◽  
Nicoleta Lupu ◽  
Gabriela Sima
Keyword(s):  
Structural Analysis ◽  
Spark Plasma Sintering ◽  
High Energy ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Detailed Structural Analysis ◽  
Plasma Sintering ◽  
High Energy Ball Mill ◽  
Spark Plasma ◽  
Energy Ball

The objective of this research is the development of a detailed structural analysis of biocomposites with ceramic matrix of hydroxyapatite (Hap) reinforced by titanium (Ti), elaborated by powder metallurgy technology. Nanometric Hap powders (<200nm) 75% wt and micrometric Ti powders (<150μm) are homogenized in a high energy ball mill Pulverisette 6. Spark plasma sintering (SPS) is the sintering route able to lead to nanostructured sintered samples when nanopowders are used as raw material. The SPS parameters are: the sintering temperature, T=(1000-1100)°C and the maintaining time, t=(10-20) minutes in vacuum. The influence of the sintering parameters on the composites structures is monitored using the optical microscopy (OM), electronic microscopy (SEM) and the X-Ray diffraction (XRD).

scholarly journals Effects of Recycled Fe2O3 Nanofiller on the Structural, Thermal, Mechanical, Dielectric, and Magnetic Properties of PTFE Matrix

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2332
Author(s):  
Ahmad Mamoun Khamis ◽  
Zulkifly Abbas ◽  
Raba’ah Syahidah Azis ◽  
Ebenezer Ekow Mensah ◽  
Ibrahim Abubakar Alhaji
Keyword(s):  
Electron Microscopy ◽  
High Energy ◽  
Filler Loading ◽  
Complex Permeability ◽  
X Ray Diffraction ◽  
Thermal Expansion Coefficients ◽  
Transmission Electron ◽  
Energy Ball ◽  
Hematite Fe2o3 ◽  
Ptfe Composites

The purpose of this study was to improve the dielectric, magnetic, and thermal properties of polytetrafluoroethylene (PTFE) composites using recycled Fe2O3 (rFe2O3) nanofiller. Hematite (Fe2O3) was recycled from mill scale waste and the particle size was reduced to 11.3 nm after 6 h of high-energy ball milling. Different compositions (5–25 wt %) of rFe2O3 nanoparticles were incorporated as a filler in the PTFE matrix through a hydraulic pressing and sintering method in order to fabricate rFe2O3–PTFE nanocomposites. The microstructure properties of rFe2O3 nanoparticles and the nanocomposites were characterized through X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). The thermal expansion coefficients (CTEs) of the PTFE matrix and nanocomposites were determined using a dilatometer apparatus. The complex permittivity and permeability were measured using rectangular waveguide connected to vector network analyzer (VNA) in the frequency range 8.2–12.4 GHz. The CTE of PTFE matrix decreased from 65.28×10−6/°C to 39.84×10−6/°C when the filler loading increased to 25 wt %. The real (ε′) and imaginary (ε″) parts of permittivity increased with the rFe2O3 loading and reached maximum values of 3.1 and 0.23 at 8 GHz when the filler loading was increased from 5 to 25 wt %. A maximum complex permeability of 1.1−j0.07 was also achieved by 25 wt % nanocomposite at 10 GHz.

scholarly journals Defect-induced B4C electrodes for high energy density supercapacitor devices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Özge Balcı ◽  
Merve Buldu ◽  
Ameen Uddin Ammar ◽  
Kamil Kiraz ◽  
Mehmet Somer ◽  
...  
Keyword(s):  
Active Carbon ◽  
High Performance ◽  
Carbon Sources ◽  
High Energy ◽  
High Energy Density ◽  
Synthesis Conditions ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
G Ratio ◽  
Energy And Power Density

AbstractBoron carbide powders were synthesized by mechanically activated annealing process using anhydrous boron oxide (B2O3) and varying carbon (C) sources such as graphite and activated carbon: The precursors were mechanically activated for different times in a high energy ball mill and reacted in an induction furnace. According to the Raman analyses of the carbon sources, the I(D)/I(G) ratio increased from ~ 0.25 to ~ 0.99, as the carbon material changed from graphite to active carbon, indicating the highly defected and disordered structure of active carbon. Complementary advanced EPR analysis of defect centers in B4C revealed that the intrinsic defects play a major role in the electrochemical performance of the supercapacitor device once they have an electrode component made of bare B4C. Depending on the starting material and synthesis conditions the conductivity, energy, and power density, as well as capacity, can be controlled hence high-performance supercapacitor devices can be produced.

A Study of Exchange-Coupling Effect on Nd2Fe14B / α-Fe Forming Core/Shell Shape

2007 ◽  
Vol 119 ◽  
pp. 147-150 ◽  
Author(s):  
Chang Woo Kim ◽  
Young Hwan Kim ◽  
Don Keun Lee ◽  
In Chul Jeong ◽  
Hae Woong Kwon ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Ball Mill ◽  
Coupling Effect ◽  
Chemical Reduction ◽  
High Energy ◽  
Shell Shape ◽  
Core Shell ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Mill Process

We report the core/shell type as the interesting one of the various techniques to prepare exchange-coupled permanent magnet. In this study, the exchange-coupled Nd2Fe14B/α-Fe was prepared by high energy ball mill process and chemical reduction. Nd15Fe77B8 powder prepared by high energy ball mill process was coated with α-Fe nanoparticle by chemical reduction. α-Fe nanoparticle on the ball milled Nd15Fe77B8 was synthesized by chemical reduction with borohydride as a reducing agent in aqueous solution. After annealing, Nd2Fe14B/α-Fe forming core/shell shape has exchange-coupling effect and was identified by using XRD, FE-SEM, VSM, TMA and EDX.

Ball milling for the formation of nanocrystalline intermetallic compounds from Ni-Ti elemental powders

2018 ◽  
Vol 27 (5-6) ◽  
Author(s):  
Pardeep Sharma
Keyword(s):  
Intermetallic Compounds ◽  
Milling Time ◽  
Lattice Strain ◽  
Research Work ◽  
High Energy ◽  
Mechanically Alloyed ◽  
Nano Crystalline ◽  
High Energy Ball Mill ◽  
Productive Process ◽  
Energy Ball

AbstractIn the present research work nickel (Ni) and titanium (Ti) elemental powder with an ostensible composition of 50% of each by weight were mechanically alloyed in a planetary high energy ball mill in diverse milling circumstances (10, 20, 30 and 60 h). The inspection exposed that increasing milling time leads to a reduction in crystallite size, and after 60 h of milling, the Ti dissolved in the Ni lattice and the NiTi (B2) phase was obtained. The lattice strain of ball milled mixtures augmented from 0.15 to 0.45 at 60 h milling. With increase in milling time the morphology of pre-alloyed powder changed from lamella to globular. Annealing of as-milled powders at 1100 K for 800 s led to the formation of NiTi (B19′), grain growth and the release of internal strain. The result indicated that this technique is a powerful and highly productive process for preparing NiTi intermetallic compounds with a nano-crystalline structure and appropriate morphology.

scholarly journals Magnetic Properties of SmCo5 + 10 wt% Fe Exchange-Coupled Nanocomposites Produced from Recycled SmCo5

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1308 ◽  
Author(s):  
Arnab Chakraborty ◽  
Răzvan Hirian ◽  
Gregor Kapun ◽  
Viorel Pop
Keyword(s):  
Heat Treatment ◽  
Exchange Coupling ◽  
Permanent Magnets ◽  
High Energy ◽  
Raw Material ◽  
Energy Ball ◽  
Hydrogen Decrepitation ◽  
Energy Products ◽  
First Time ◽  
Recycled Material

Nanostructured alloy powders of SmCo5 + 10 wt% Fe obtained using recycled material were studied for the first time. The SmCo5 precursor was obtained from commercial magnets recycled by hydrogen decrepitation. The results were compared with identically processed samples obtained using virgin SmCo5 raw material. The samples were synthesized by dry high-energy ball-milling and subsequent heat treatment. Robust soft/hard exchange coupling was observed—with large coercivity, which is essential for commercial permanent magnets. The obtained energy products for the recycled material fall between 80% and 95% of those obtained when using virgin SmCo5, depending on milling and annealing times. These results further offer viability of recycling and sustainability in production. These powders and processes are therefore candidates for the next generation of specialized and nanostructured exchange-coupled bulk industrial magnets.

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