scholarly journals Pengaruh waktu milling terhadap Sifat mikro struktur dan magnet dari NdFeB dengan proses Wet dan Dry milling

2021 ◽  
Vol 9 (1) ◽  
pp. 9-16
Author(s):  
Wahyu Solafide Sipahutar ◽  
◽  
William William ◽  
Muljadi Muljadi ◽  
◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Magnetic Flux ◽  
Time Variation ◽  
Annealing Temperature ◽  
Milling Time ◽  
Dry Milling ◽  
Wet Milling ◽  
Milling Method

Making of magnets from NdFeB flakes by Wet and dry milling to determine the microstructure, physical and magnetic properties of the milling time variation is 16, 24, and 48 hours. The milling powder is then analysed to determine the particle size with PSA and XRD to determine the phase formed. Then the compacting process with isotropy printing for making pellet test samples with a pressure of 7 tons for 2 minutes. Then the pellet sample, given annealing temperature with a variation of 150 and 170 ̊C, then a measurement of magnetic properties with a Gauss Meter. The results obtained by the smallest optimum particle size with 48 hours of milling time at a diameter of 90% 4.7 μm, while the results of dry milling at a diameter of 90% amounted to 60.85 μm. The best method to get the smallest particle size is the Wet milling method. XRD results with Wet and Dry milling phases that appear only Nd2Fe14B phase. As milling time increases, the resulting density increases. The largest magnetic flux testing with dry milling method with 48 hours of milling time for temperatures 170 ̊C temperature obtained 468.5 Gauss and the addition of annealing temperature the magnetic properties of the material is getting better.

Annealing Effects on the Physical and Magnetic Properties of Tb1.5Y1.5Fe5O12 Films Nanoparticles Prepared by Sol-Gel Method

2013 ◽  
Vol 756 ◽  
pp. 91-98 ◽  
Author(s):  
Ftema W. Aldbea ◽  
Noor Bahyah Ibrahim ◽  
Mustafa Hj. Abdullah
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Annealing Temperature ◽  
Quartz Substrate ◽  
Sol Gel ◽  
Lattice Parameter ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Iron Garnet

Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900 °C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900°C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-raySpectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealingtemperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. Normal 0 21 false false false MS X-NONE X-NONE MicrosoftInternetExplorer4 Terbium –substituted yttrium iron garnet (Tb1.5Y1.5Fe5O12) films nanoparticles were successfully prepared by a sol-gel method. The films were deposited on the quartz substrate using spin coating technique. To study effect of annealing temperature, the annealing process was executed at 700, 800 and 900°C in air for 2 hours. The X-ray diffraction (XRD) proved that the pure phase of garnet structure was detected for the film annealed at 900 °C. The lattice parameter increased with the increment of annealing temperature and the highest value of 12.35 Å was obtained at 900 °C. Field Emission Scanning Electron Microscope (FE-SEM) results showed that the particle size increased from 43nm to 56nm as annealing temperature increased from 700 to 900 °C. The film’s thickness also affected by increasing of annealing temperature and become thin at 900 °C due to densification process occurred at high annealing temperature. The elemental compositions of the Tb1.5Y1.5Fe5O12 film were detected using an Energy Dispersive X-ray Spectroscopy (EDX). Magnetic properties at room temperature were measured using a Vibrating Sample Magnetometer (VSM).The saturation magnetization Ms increased with the annealing temperature and showed a high value of 104emu/cm3, but the coercivity Hc of the film was decreased due to the increment of the particle size. st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

Benefits of Mild Wet Milling of the Intermediates for the Synthesis of Phase-pure Z-type Hexaferrite

2005 ◽  
Vol 20 (8) ◽  
pp. 1939-1942 ◽  
Author(s):  
Jadambaa Temuujin ◽  
Masami Aoyama ◽  
Mamoru Senna ◽  
Taisuke Masuko ◽  
Chie Ando ◽  
...  
Keyword(s):  
Particle Size ◽  
Crystallization Rate ◽  
Planetary Mill ◽  
Favorable Effect ◽  
Dry Milling ◽  
Wet Milling ◽  
Diffusion Distance ◽  
Particle Size Reduction ◽  
Phase Pure ◽  
Basic Layer

A comparative study on the wet and dry milling of the intermediates for the Z-type hexagonal ferrite (Ba3Co2Fe24O41, Z phase) was performed. Phase-pure Z phase was synthesized by wet milling the intermediates comprising M and Y-type hexaferrites. The intermediates were obtained by calcining the stoichiometric powder mixture at 1080 °C. Subsequent wet milling by a planetary mill for 1 h increased the crystallization rate of Z phase upon subsequent heating at 1230 °C. In contrast, dry milling the intermediates resulted in the severe surface amorphization and led to heterogeneous crystalline states. The observed favorable effect of wet milling the intermediates was explained by the particle size reduction for the decrease of diffusion distance while preserving the basic layer units common to the related hexaferrites.

The Effect of Milling Time on Physical Properties, Magnetic Properties and Microstructure of Bonded Magnet BaFe12O19

2020 ◽  
Vol 855 ◽  
pp. 34-39
Author(s):  
Suprapedi ◽  
Muljadi ◽  
Priyo Sardjono ◽  
Ramlan Ramlan
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Particle Size Distribution ◽  
Physical Properties ◽  
Bulk Density ◽  
Ball Mill ◽  
Milling Time ◽  
Mixed Powder ◽  
Bonded Magnet

A bonded permanent magnet of Barium hexa Ferrite has been made using powder BaFe12O19 (commercial ferrite) and a polymer of bakelite powder as binder. The composition of bakelite was varried 5% wt. The preparation of sample was begun with mass weighing for each material, then mixed together using ball mill for 1, 6 and 12 hours and using aquades as milling media. The mixed powder is dried in an oven at 110 °C for 4 hours, then the particle size distribution was measured. After that, the dried sample powder was pressed to form a pellet at pressure 40 MPa and temperature about 160 °C for 20 minutes. The characterization of sample pellet was done such as measurement of bulk density, hardness , magnetic properties using VSM and anylisis of microstructure using SEM. The results of the characterization show that the density and magnetic properties tend to increase with increasing of milling time, where the highest density, hardness and highest magnetic properties are achieved at sample with milling time for 12 hours. The value of magnetic properties at this condition are flux magnetic of 530 Gauss, remenance of 3100 Gauss, coercivity of 1,10 kOe.

scholarly journals Influence of the Oxide and Ethanol Surface Layer on Phase Transformation of Al-Based Nanocomposite Powders under High-Energy Milling

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1305 ◽  
Author(s):  
Dora Janovszky
Keyword(s):  
Particle Size ◽  
Milling Time ◽  
High Energy ◽  
Amorphous Structure ◽  
Control Agent ◽  
Dry Milling ◽  
Process Control Agent ◽  
Composite Powders ◽  
High Energy Milling ◽  
Nanocomposite Powders

Pure Al particles reinforced with amorphous-nanocrystalline Cu36Zr48Ag8Al8 particles composite powders were prepared by high-energy milling without and with ethanol. The mechanical milling procedures were compared so that in the case of dry milling the particle size increased owing to cold welding, but the crystallite size decreased below 113 nm. The amorphous phase disappeared and was not developed until 30 h of milling time. Using ethanol as a process control agent, the particle size did not increase, while the amorphous fraction increased to 15 wt.%. Ethanol decomposed to carbon dioxide, water, and ethane. Its addition was necessary to increase the amount of the amorphous structure.

Synthesis and Characterization of Electromagnetic Material Based On Composite of Barium M-Ferrite and Zinc Oxide

2018 ◽  
pp. 78-82
Author(s):  
Verryon Harahap ◽  
Syahrul Humaidi ◽  
Perdamean Sebayang
Keyword(s):  
Zinc Oxide ◽  
Magnetic Properties ◽  
High Energy ◽  
Lattice Parameter ◽  
Milling Process ◽  
Raw Material ◽  
Wet Milling ◽  
Hexagonal Crystal ◽  
Milling Method ◽  
Energy Products

The making of composites BaFe12O19/ZnO has been done with Wet Milling method used media toluene. Barium M-Ferrit as a matrix and Zinc Oxide as a filler used as the main raw material for composite manufacturing. The milling process of Barium M-Ferrit was done for 12 hours using the High Energy Milling (HEM). Furthermore, the calcination process used furnace at 900 ° C for 4 hours. While Zinc Oxide is milled for 3 hours and calcined at a temperature of 500 oC for 3 hours. The results of Barium M-Ferrit and zinc Oxide mixed using wet milling touluene media for 15 minutes and dried for 1 hour at 200 oC. X-ray diffraction (XRD) showed that BaFe12O19 as a matrix and ZnO as filler with hexagonal crystal structure was formed and the peak showed a single phase, where each BaFe12O19 lattice parameter a = 5.8930 Å, c = 23.1940 Å and ZnO lattice parameter a = 3.2533 Å, c = 5.2073 Å. Characterization Vibrating Sample Magnetometer (VSM) obtained the value of magnetic properties BaFe12O19 powder (matrix) obtained (Ms) magnetic saturation 54.03 emu/g, (Mr) magnet remanent 33.06 emu/g, (Hcj) coercivity 2943 Oe and (BHmax) product energy 190 kGOe and Zinc Oxide as filler values (Ms) magnet saturation 7.84 emu / g, (Mr) magnet remanent 1.27 emu/g, (Hcj) coercivity 152.4 Oe and (BHmax) energy products 10 kGOe. The results of XRD on 50% mass of composites ZnO additions using match software have two phases, namely the presence of ZnO and BaFe12O19 phases which indicate that heterogeneous structures with hexagonal crystal structures. Composite magnetic properties obtained by adding 50% mass of ZnO were (Mr) magnet 39.40 emu/ g, coercivity 2728 Oe, (BHmax) product energy 110 kGOe and for composites 75% mass addition ZnO remanent 39.36 emu/g with coefficient of 1365 Oe and ( BHmax) product energy was 60 kGOe.

Effect of Dispersants on Microstructures of Nano Alpha Alumina Developed from Aluminium Dross Waste

2015 ◽  
Vol 1115 ◽  
pp. 378-381 ◽  
Author(s):  
S. Anis Sofia ◽  
Noorasikin Samat ◽  
Meor Yusoff Meor Sulaiman
Keyword(s):  
Particle Size ◽  
Xrd Analysis ◽  
Planetary Mill ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Milling Method ◽  
Aluminium Dross ◽  
Alpha Alumina

This paper compares the effect of dispersants which are Sodium Laureth Sulfate (SLS) and distilled water (DW) on the crystallization, particle size distribution and morphological behavior of nanoalpha Alumina (α-Al2O3) synthesized from Aluminium (Al) dross waste. The synthesizing of nanoα-Al2O3 via wet milling method was performed using a planetary mill for 4 hours at a speed of 550 rpm. The nanoα-Al2O3 powders with dispersants were characterized with x-ray diffraction (XRD), particle size analyzer (PSA) and transmission electron microscopy (TEM). XRD analysis shows the broadening and shifting of peaks after the sample was calcined at 1300 °C, indicating high crystallinity. The crystallite size of α-Al2O3 milled with SLS is also smaller than the α-Al2O3 milled with DW. These results are consistent with the PSA analysis in which the graphs displayed a symmetrical trend. Then, the PSA analysis is validated with TEM observation up to 100000x magnification, particularly for α-Al2O3 milled with SLS.

Effect of Milling in Various Media and Annealing on the Structure and Magnetic Properties of Strontium Hexaferrite Powder

2012 ◽  
Vol 190 ◽  
pp. 183-187 ◽  
Author(s):  
S.V. Ketov ◽  
E.A. Lopatina ◽  
T.A. Bulatov ◽  
Yu.D. Yagodkin ◽  
V.P. Menushenkov
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Oleic Acid ◽  
Milling Time ◽  
Strontium Hexaferrite ◽  
Powder Particle Size ◽  
Nanocrystalline State ◽  
Abrupt Decrease ◽  
Phase Type ◽  
Crystallite Sizes

In the present work, the structure and magnetic properties of strontium hexaferrite powder during milling in various media and subsequent annealing were studied. The milling of the powder leads to an abrupt decrease in the powder particle size and the average crystallite sizes as well as an increase in lattice microstrains of the SrFe12O19 phase. During milling in toluene, no changes in the phase composition were observed, whereas, during milling in water, the Fe2O3 phase (type H1.1) is formed. In the powder milled in oleic-acid-containing toluene a small quantity of α-Fe was found. After milling, the saturation magnetization and remanence decrease; at the same time, the coercive force of the powder milled in toluene is unchanged with increasing milling time, but slightly increases after milling in water and in oleic-acid-containing toluene. The annealing allowed us to increase the magnetic properties of the powder. It is conditioned by formation of nanocrystalline state. Moreover, the magnetic properties values depend on the medium and time of milling. The annealed powders are characterized by the following magnetic properties: μ0Нci = 0.42 ÷ 0.49 T, Br = 0.23 ÷ 0.24 T, (BH)max = 8-9.6 kJ/m3.

Investigation of Particle Size Effects on the Magnetic Properties and Corrosion Behaviour of Mechanically Alloyed Nd-Fe-B Powder

2006 ◽  
Vol 306-308 ◽  
pp. 971-976
Author(s):  
H.K. Jun ◽  
Iskandar Idris Yaacob
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Milling Time ◽  
Corrosion Behaviour ◽  
Amorphous State ◽  
Surface Damage ◽  
Mass Gain ◽  
Mechanically Alloyed ◽  
Xrd Pattern ◽  
Lower Particle Size

Elemental powders of Nd, Fe and B were mechanically alloyed using a planetary ball mill. The change of structure and particle size was examined. XRD pattern revealed that with prolong milling, the mixture of the powders was transformed to nearly amorphous state. Smaller particle size was observed with prolong milling. Magnetization of the mixture of powders was studied using AGM. The saturation magnetization of the mixture was observed to increase initially and then decrease with increasing milling time. The reduction of the magnetic properties was suspected to be due to surface damage which was incurred by extensive milling. The corrosion rate was observed to be higher for larger particle size (low milling time). This indicated higher mass gain percentage of larger particle size compared to lower particle size. The magnetic properties however, did not should any significant improvement after corrosion effect.

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