Synthesis of Nickel/Ba-Hexaferrite Magnetic Nano-Composite via Mechanical Alloying Route

2013 ◽  
Vol 829 ◽  
pp. 520-524
Author(s):  
Issa Sobhani ◽  
Abolghasem Ataie ◽  
Mahdiye Ijavi ◽  
Zoya Sadighi

In this study, nickel and Ba-hexaferrite powders were subjected to high energy mechanical milling in argon atmosphere to produce nickel/Ba-hexaferrite magnetic nanocomposite. Effects of milling time and Ni amount on the phase evolution, morphology and magnetic properties of the products have been investigated by XRD, FESEM/SEM and VSM, respectively. XRD analysis of nanocomposite indicated only Ni peaks after 5 h milling which implied the embedding of Ba-hexaferrite particles inside the metallic nickel. FESEM results revealed that the increasing of the milling time up to 30 h reduced nanocomposite particles size into 20 nm. VSM results showed that the magnetic properties of the nickel/Ba-hexaferrite nanocomposite were affected by the process conditions. The highest saturation magnetization (33.8emu/g) was obtained for the sample containing 30 wt% Ni milled for 20 h Ni series of powder mixture. In addition, it was found that by increasing the milling time coercive field decreases.

This research was conducted to produce the magnetite (Fe3O4 ) nanoparticles extracted from the industrial millscale waste. Then, the micron size samples were extracted and grounded on the high energy ball milling (HEBM) at various milling time for 4, 8, 12, 16 and 20 h. The formation of nanosized single-phase hexagonal spinel has been observed with XRD analysis as early as 4 h milling time. The FTIR transmission spectrum shows the appearance of a Fe-O functional group for each sample. HRTEM images showed that all the samples had a small particle size of 5-20 nm with uniform distribution. The specific surface area of the 5 adsorbents increased after the 8 h milling time and it showed reduction after that. The magnetite adsorbents then utilized the adsorbent in Cadmium ions removal of the aqueous solution. Fe3O4 with 8 h milling time was able to remove 9.81 mg of cadmium ions with 1 g of adsorbents consume. The removal of the cadmium ions detected related to the particles size, surface areas and saturation magnetization. This research successfully revealed that the higher saturation magnetization contributed to high removal percentages in cadmium ions of aqueous solutions. Fe3O4 extraction from mill scales waste is cost-effective, the process is eco-friendly and thus, potentially to be applied for wastewater treatment.


Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1679
Author(s):  
Kaouther Zaara ◽  
Mohamed Khitouni ◽  
Lluisa Escoda ◽  
Joan Saurina ◽  
Joan-Josep Suñol ◽  
...  

The nanocrystalline Fe70Ni12B16Si2 (at.%) alloy was prepared by mechanical alloying (MA) of elemental powders in a high-energy planetary ball mill. Phase evolution, microstructure, thermal behavior and magnetic properties were investigated. It was found that a body-centered cubic structured solid solution started to form after 25 h milling and a faced-centered cubic structure solid solution started to form after 50 h of milling; its amount increased gradually with increasing milling time. The BCC and the FCC phases coexisted after 150 h of milling, with a refined microstructure of 13 nm and a 10 nm crystallite size. The as-milled powder was annealed at 450 °C and 650 °C and then investigated by vibrating sample magnetometry (VSM). It was shown that the semi-hard magnetic properties are affected by the phase transformation on annealing. The saturation magnetization decreases after annealing at 450 °C, whereas annealing at 650 °C improves the magnetic properties of 150 h milled powders through the reduction of coercivity from 109 Oe to 70 Oe and the increase in saturation magnetization.


1992 ◽  
Vol 274 ◽  
Author(s):  
C. P. Reed ◽  
S. C. Axtell ◽  
R. J. De Angelis ◽  
B. W. Robertson ◽  
V. V. Munteanu ◽  
...  

AbstractMetal powders of the composition 70 at% Cu and 30 at% Fe were produced by high energy mechanical alloying of the elemental powders. The powders were processed in a Spex 8000 mixer/mill for various times to investigate the potential of the mechanical alloying process for producing nano-composite structures with modified magnetic properties. Optical microscopy revealed a layered structure of alternating copper and iron that developed upon milling. The spacing between the layers decreased with milling time, becoming optically unresolvable (< 1 μm) after four hours of milling. A single profile x-ray diffraction profile shape analysis technique was used to determine the average diffracting particle size of the copper and iron phases. The diffracting particle size decreases with alloying time reaching values of 7.5 nm and 2 nm, for copper and iron respectively, after eight hours of alloying. The magnetic coercivity increased with milling time initially, reaching a maximum value above 300 Oe after six hours of milling. These results are discussed and compared to results obtained in Ag/Fe and Cu/Fe nano-composite films.


2010 ◽  
Vol 434-435 ◽  
pp. 354-356 ◽  
Author(s):  
M.J. Molaei ◽  
Abolghasem Ataie ◽  
Sh. Raygan

In this work, nano-composite of barium hexaferrite/magnetite was produced by partial reduction of barium hexaferrite with graphite via ball milling. Phase composition, morphology and magnetic properties of the samples were evaluated by XRD, SEM and VSM, respectively. XRD results revealed that after 15 hours milling, a nano-composite of BaFe12O19/Fe3O4 formed which mean crystallite size of BaFe12O19 was 17 nm. After milling for 20 and 40 hours, the peaks of BaFe12O19 were weakened and Fe3O4 was detected as a dominant phase. The coercivity decreased from 703 to 153 Oe when the milling time increased from 15 to 20 hours.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1383-1388 ◽  
Author(s):  
MASLEEYATI YUSOP ◽  
DELIANG ZHANG ◽  
MARCUS WILSON ◽  
NICK STRICKLAND

Al 2 O 3-20 vol % Fe 70 Co 30 composite powders have been prepared by high energy ball milling a mixture of Al 2 O 3 powder and Fe 70 Co 30 alloy powder. The Fe 70 Co 30 alloy powder was also prepared by mechanical alloying of Fe and Co powders using the same process. The effects of milling duration from 8 to 48 hours on microstructure and magnetic properties of the nanostructured composite powders have been studied by means of X-ray Diffractometry (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). It was found that the nanostructured composite powder particles with irregular shapes and Fe 70 Co 30 alloy particles being embedded in them formed after 8 hours of milling. The average grain size of the Al 2 O 3 matrix reduced drastically to less than 18nm after 16 hours of milling. On the other hand, the embedded alloy particles demonstrated almost unchanged average grain size in the range of 14-15nm. Magnetic properties of the powder compacts at room temperature were measured from hysteresis curves, and show strong dependence of the milling time, with the coercivity increasing from 67.1 up to 127.9kOe with increasing the milling time from 8 to 48 hours. The possible microstructural reasons for this dependence are discussed.


2012 ◽  
Vol 727-728 ◽  
pp. 206-209
Author(s):  
Osvaldo Mitsuyuki Cintho ◽  
H.I. Tsai ◽  
M. Bär ◽  
M. de Castro ◽  
E.F. Monlevade ◽  
...  

High energy ball milling has been used like alternative route for processing of materials. In the present paper, the reduction of tungsten oxide by aluminum in order to obtain metallic tungsten was studied using a SPEX type high energy mill. A powdered mixture of WO3and metallic aluminum, weighed according to the stoichiometric proportion with an excess 10% Al, was processed with hardened steel utensils using a 1:6 powder-to-ball ratio. The processing was carried out with milling jar temperature measurement in order to detect the reaction type. The temperature evaluation indicated the self-propagating reaction occurrence by fast increase of the jar temperature after a short milling time. The tungsten oxide reduction was verified by X-Ray Diffraction (XRD) analysis and the milling products were characterized by Scanning Electron Microscopy (SEM). The results were slightly different from the literature due to the mill type and milling parameters used in the work.


2011 ◽  
Vol 287-290 ◽  
pp. 1492-1495 ◽  
Author(s):  
Hai Xia Wang ◽  
Ping Zhan Si ◽  
Wei Jiang ◽  
Jin Jun Liu ◽  
Jung Goo Lee ◽  
...  

Novel nano-composite powders composed of hard-magnetic Mn54Al46 and soft-magnetic α-Fe were prepared by high-energy ball milling. The effect of α-Fe and preparation conditions on the structure and magnetic properties of the composite powders has been investigated. The ε-MnAl transforms to γ-MnAl, τ-MnAl, and β-phase under ball milling and annealing. The saturation magnetization and coercivity of the two-phase samples decrease with increasing temperature for the τ-phase decomposes at elevated temperatures. With increasing iron content, the coercivity decrease first and then increase up to 0.33 T when the Fe content is 10 wt%. Further addition of the magnetically soft iron phase would result in a decrease of the coercivity.


2003 ◽  
Vol 788 ◽  
Author(s):  
Shashishekar Basavaraju ◽  
Ian Baker

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.


Author(s):  
F. Kristaly ◽  
M. Sveda ◽  
A. Sycheva ◽  
T. Miko ◽  
A. Racz ◽  
...  

Ti50Cu25Ni20Sn5 (at.%) powder was subjected to high-energy ball milling at room temperature and -78?C. As a function of the milling time, evaluation of phases, morphology and the refinement of grain size were investigated by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and laser-diffraction particle size analysis (PSA). The transformation of the crystalline structure into an amorphous structure and then the transformation into a nanocrystalline structure during further milling was detected. The stress-induced martensitic transformation has taken place after 30 min milling time at both temperatures, the cubic Cu(Ni,Cu)Ti2 phase transforms into the orthogonal structure. The hardness value of powders after 150 min milling time increases from 506 to 780 HV0.01. The milling temperature does not significantly influence the amount of amorphous fraction (33-36 wt.%) but the composition of amorphous content is more influenced by temperature. The interval of crystallite size was between 1.2 and 11.7 nm after 180 min of milling. The amount and the cell parameters of the Sn-containing phases are different between the two milling experiments, owing to the diffusion coefficients of the Sn atom differ to a large extent.


2017 ◽  
Vol 47 ◽  
pp. 79-88 ◽  
Author(s):  
Z. Hamlati ◽  
W. Laslouni ◽  
Mohammed Azzaz ◽  
M. Zergoug ◽  
D. Martínez-Blanco ◽  
...  

Ternary Fe72Al26Sn2 and Cu70Fe18Co12 alloys were obtained by mechanical alloying of pure Fe, Al, Sn, Cu and Co powders using a high energy ball mill. X-ray diffraction and electron microscopy supported by magnetic measurements have been applied to follow changes in the microstructure, phase composition and magnetic properties in dependence on milling time. With the increase of milling time all Al and Sn atoms dissolved in the bcc Fe and the final product of the MA process was the nanocrystalline Fe (Al, Sn) solid solution in a metastable state with a large amount of defects and mean crystallite size of 5 nm. However, the obtained crystallite size value is about 10 nm for the ball milled Cu70Fe18Co12 powders. The electron microscope observations show the morphology of powder particles. Magnetic properties of the nanocrystalline mechanically alloyed FeAlSn and CuFeCo were also investigated and were related to the microstructural changes.


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