Preparation and Characterization of Hybrid Bonded Magnet Ba-Ferrite/NdFeB with Epoxy Resin

2016 ◽  
Vol 864 ◽  
pp. 65-69 ◽  
Author(s):  
Muljadi ◽  
Priyo Sardjono ◽  
Nenen Rusnaeni Djauhari ◽  
Suprapedi ◽  
Ramlan
Keyword(s):  
Magnetic Properties ◽  
Epoxy Resin ◽  
Bulk Density ◽  
Magnetic Particle ◽  
Weight Ratio ◽  
Hydraulic Press ◽  
Polymer Binder ◽  
Composition Ratio ◽  
Bonded Magnet

Hybrid bonded magnet Ba-Ferrite/NdFeB with 5% wt Epoxy Resin (ER) as polymer binder hsa been developed with variations in BaFe12O19 to NdFeB weight ratio. The variation of the BaO6Fe2O3 : Nd-Fe-B weight ratio are 90%:10%; 80%:20%; 70%:30% and 60%:40%. The magnetic particle consist of Ba-Ferrite and NdFeB were mixed until homogenize and compacted by using hydraulic press machine with 8 Tonf force to form a disc shape sample. The disc sample was dried using vacuum dryer with 10 mm bar pressure at 80°C for one hour before being magnetized using impulse magnetizer. The best %wt composition ratio of Ba-Ferrite/NdFeB is 70%/30% and 60%/40%. The hybrid bonded magnetic properties at the best %wt composition ratio are: bulk density = 4.28-4.43 g/cm3, FM = 1057-1121 Gauss, Br = 3.46-3.70 kG, Hc = 3.25-3.70 kOe, and BHmax = 1.60-1.70 MGOe.

Analysis Magnetic Properties and Corrosion Resistance of Hybrid Bonded Magnet BaFe12O19-NdFeB

2020 ◽  
Vol 855 ◽  
pp. 28-33
Author(s):  
Ramlan Ramlan ◽  
Dedi Setiabudidaya ◽  
A.A.A. Bama ◽  
Muljadi
Keyword(s):  
Corrosion Resistance ◽  
Bulk Density ◽  
Permanent Magnets ◽  
Raw Materials ◽  
Weight Ratio ◽  
Hydraulic Press ◽  
Mixed Powder ◽  
Vacuum Oven ◽  
Bonded Magnet

Permanent Magnets made in the form of hybrid bonded BaFe12O19 / NdFeB and with binder of Poli Vynil Alcohol (PVA) as much as 3% of the total mass in each sample. The weight ratio hybride system BaFe12O19 : NdFeB is 0 % BaFe12O19 : 100 % NdFeB ; 50% BaFe12O19 : 50 % NdFeB and 70% BaFe12O19 : 30 % NdFeB. The material preparation process was begun from mixing of raw materials using HEM for 15 minutes, then added 3% wt. of PVA. The mixed powder was formed a pellet using a hydraulic press with a force of 4 tons for 1 minute, then heated with an vacuum oven at a temperature of 110 ° C for 1 hour and the last step was magnetization using impulse magnetizer. The characterization of pellet sample was done namely measurement of bulk density, flux magnetic and hysteresis loop using VSM and then measurement of corrosion resistance of hybride bonded magnet. The characterization results show that bulk density value of sample hybride 50% BaFe12O19 – 50 % NdFeB is more larger than sample hybride 70% BaFe12O19 – 30 % NdFeB , and The highest coercivity and remanence values ​​of 3900 Oe and 2500 Gauss respectively were achieved in samples with a composition of 50% Ba-ferrite - 50% NdFeB. The hybride bonded magnet Ba-ferrite/NdFeB has more corrosion resistance than bonded magnet 100 % NdFeB.

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 Novel Benchtop Magnetic Particle Spectrometer for Process Monitoring of Magnetic Nanoparticle Synthesis

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2277
Author(s):  
Norbert Löwa ◽  
Dirk Gutkelch ◽  
Ernst-Albrecht Welge ◽  
Roland Welz ◽  
Florian Meier ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Process Monitoring ◽  
Magnetic Nanoparticle ◽  
Magnetic Particle ◽  
Nanoparticle Synthesis ◽  
Separation Processes ◽  
Magnetic Detector ◽  
Application Fields

Magnetic nanoparticles combine unique magnetic properties that can be used in a variety of biomedical applications for therapy and diagnostics. These applications place high demands on the magnetic properties of nanoparticles. Thus, research, development, and quality assurance of magnetic nanoparticles requires powerful analytical methods that are capable of detecting relevant structural and, above all, magnetic parameters. By directly coupling nanoparticle synthesis with magnetic detectors, relevant nanoparticle properties can be obtained and evaluated, and adjustments can be made to the manufacturing process in real time. This work presents a sensitive and fast magnetic detector for online characterization of magnetic nanoparticles during their continuous micromixer synthesis. The detector is based on the measurement of the nonlinear dynamic magnetic response of magnetic nanoparticles exposed to an oscillating excitation at a frequency of 25 kHz, a technique also known as magnetic particle spectroscopy. Our results underline the excellent suitability of the developed magnetic online detection for coupling with magnetic nanoparticle synthesis based on the micromixer approach. The proven practicability and reliability of the detector for process monitoring forms the basis for further application fields, e.g., as a monitoring tool for chromatographic separation processes.

scholarly journals Bonded Magnet Permanen Nd2Fe14B dengan Perekat Silicone Rubber dan Karakterisasinya

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Djuahana
Keyword(s):  
Magnetic Properties ◽  
Permanent Magnet ◽  
Bulk Density ◽  
Silicone Rubber ◽  
Room Temperature ◽  
Raw Materials ◽  
Hysteresis Curve ◽  
Bonded Magnet

Abstrak: Bonded magnet permanen dibuat dengan variasi: 95 %wt. Nd2Fe14B dengan 5% SR, 90 %wt. Nd2Fe14B dengan10% SR, 85 %wt. Nd2Fe14B dengan 15% SR, dan 80 %wt. Nd2Fe14B dengan 20% SR. Kedua bahan baku dicampur denganmenggunakan mixer hingga homogen dan berbentuk pasta. Selanjutnya, campuran tersebut dituang ke dalam cetakan dandibiarkan pada suhu ruang selama 4 jam. Sampel yang telah kering dikeluarkan dari cetakan dan dikarakterisasi melaluipengukuran bulk density dan pengukuran kurva histerisis menggunakan BH-curve Permeagraph. Hasil XRD serbuk Nd2Fe14B(NQP-B) yang dianalisis dengan program GSAS diperoleh bahwa serbuk tersebut memiliki komposisi fasa Nd2Fe14B = 78,14%dan fasa Fe = 21,86%. Komposisi silicone rubber (SR) memberikan pengaruh yang signifikan terhadap nilai bulk density dan3sifat magnetiknya. Sampel dengan 5% berat SR memiliki bulk density terbesar yaitu = 4,67 g/cm, sampel dengan 10% sampai3320% berat SR memiliki nilai bulk density yang lebih rendah yaitu masing masing 3,12 g/cm sampai 3,72 g/cm. Hasil darikurva histerisis BH-curve menunjukkan bahwa semakin banyak persentase SR maka sifat magnetiknya cenderung menurun.Nilai remanansi tertinggi (Br ) adalah = 4,85 kG pada sampel dengan 5% berat SR, tetapi sampel dengan 20% berat SR memilikinilai Br terendah yaitu 2,47 kG.Kata Kunci: magnet permanen, Nd2Fe14B, silicone rubber, BH-curveAbstract: Bonded permanent magnet has been made by using composition: 95 wt.% Nd2Fe14B with 5% SR, 90 wt.% Nd2Fe14Bwith 10% SR, 85 wt.% Nd2Fe14B with 15% SR, and 80 wt.% Nd2Fe14B with 20% SR. Both raw materials were mixed untilhomogen and formed a pasta. Then the pasta was casted to mould and dried at room temperature for 4 hours. The driedsamples were released from the mould and continued with characterization for measurement of bulk density and measurementof hysteresis by using BH-curve permeagraph. The XRD result of Nd2Fe14B (NQP-B) shows that the powder of Nd2Fe14B(NQP-B) contains phases : Nd2Fe14B = 78.14% and Fe = 21.86%. The composition of silicone rubber (SR) influences3siqnificantly to bulk density and magnetic properties. Sample with 5 % of SR has highest bulk density (4.67 g/cm), sample33with 10 % to 20 % of SR have lowest bulk density value, respectively: 3.12 g/cm and 3.72 g/cm. The results of measurementof hysteresis curve found that the amount of SR is more higher so the magnetic properties decline. The highest value ofremanence is 4.85 kG at samples with 5 wt.% of SR, but sample with 20 wt.% of SR has lowest value of remanence (2.47 kG).Keywords: permanent magnet, Nd2Fe14B, silicone rubber, BH-curve

scholarly journals Efek Penambahan Fe3Mn7 Terhadap Sifat Fisis dan Mekanik α-Fe2O3

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Eko Arief Setiadi
Keyword(s):  
Magnetic Properties ◽  
Bulk Density ◽  
Major Phase ◽  
Magnetization Saturation ◽  
Hard Magnet ◽  
Saturation Remanence ◽  
Optimum Sample

Abstrak: Preparasi dan karakterisasi pellet α-Fe2O3 dengan penambahan 0, 2, 5 dan 10 %wt. Fe3Mn7 berbasis pada materialalam telah berhasil dilakukan. Proses pencampuran serbuk α-Fe2O3 dan Fe3Mn7 dilakukan dengan menggunakan HEM. ºKemudian campuran serbuk dikasinasi pada suhu 1000C, dikompaksi pada 69 Pa hingga menjadi pellet dan disinter padasuhu 1000 ºC. Karakterisasi XRD menunjukkan adanya fasa dominan α-Fe2O3 dan fasa baru MnO2 dan Fe3O4. Densitas dankekerasan sampel meningkat secara linier seiring dengan kenaikan komposisi Fe3Mn7 yang ditambahkan. Sampel optimum3diperoleh pada sampel α-Fe2O3/10 %wt. Fe3Mn7 dengan nilai bulk density dan kekerasan masing-masing 4,98 g/cm and994,94 HV. Sampel ini termasuk dalam klasifikasi hard magnet dengan nilai magnetisasi saturasi, remanen dan koersivitasmasing-masing sebesar 24,0 emu/g, 10,3 emu/g dan 571,8 Oe.Kata kunci:. α-Fe2O3, Fe3Mn7, densitas, kekerasan, sifat magnetikAbstract: Preparation and characterization of α-Fe2O3 pellet with the addition of 0, 2, 5 and 10 %wt. Fe3Mn7 based on naturalmaterials have been successfully carried out. The process of mixing powder of α-Fe2O3 and Fe3Mn7 was performed usingºHEM. Then, the mix powders were calcined at temperature of 1000 C. After that, the powders were compacted at 69 Pa intopellet and sintered at temperature of 1000ºC. Characterization of XRD shows that the samples have major phase of α-Fe2O3and new phases of MnO2 and Fe3O4. The density and hardness samples increase linearly with increasing of Fe3Mn73composition. The optimum sample with α-Fe2O3/10 %wt. Fe3Mn7 has bulk density and hardness value of 4.98 g/cm and 994.94HV respectively. This sample is classified as semi-hard magnet with magnetization saturation, remanence and coercivity valueof 24.0 emu/g, 10.3 emu/g dan 571.8 Oe respectively.Keywords: α-Fe2O3, Fe3Mn7, density, hardness, magnetic properties

scholarly journals Preparation and Characterization of Microcrystalline Wax/Epoxy Resin Microcapsules for Self-Healing of Cementitious Materials

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1725
Author(s):  
Wei Du ◽  
Quantao Liu ◽  
Runsheng Lin ◽  
Xin Su
Keyword(s):  
Epoxy Resin ◽  
Size Distribution ◽  
Weight Ratio ◽  
Cementitious Materials ◽  
Self Healing ◽  
Surface Cracks ◽  
Preparation Temperature ◽  
Core Content ◽  
Healing Agent

Self-healing of cracks in cementitious materials using healing agents encapsulated in microcapsules is an intelligent and effective method. In this study, microcapsules were prepared by the melt–dispersion–condensation method using microcrystalline wax as the shell and E-51 epoxy resin as the healing agent. The effects of preparation process parameters and microcrystalline wax/E-51 epoxy resin weight ratio on the core content, particle size distribution, thermal properties, morphology, and chemical composition of microcapsules were investigated. The results indicated that the optimal parameters of the microcapsule were microcrystalline wax/E-51 epoxy resin weight ratio of 1:1.2, stirring speed of 900 rpm, and preparation temperature of 105 °C. The effects of microcapsules on pore size distribution, pore structure, mechanical properties, permeability, and ultrasonic amplitude of mortar were determined, and the self-healing ability of mortar with different contents of microcapsules was evaluated. The optimal content of microcapsules in mortars was 4% of the cement weight, and the surface cracks of mortar containing microcapsules with an initial width of 0.28 mm were self-healed within three days, indicating that microcapsules have excellent self-healing ability for cementitious materials.

Hydrostatic Training and Characterization of near Stoichiometric Ni-Mn-Ga Alloy

2020 ◽  
Vol 835 ◽  
pp. 22-27
Author(s):  
Nour Mahmoud Eldabah ◽  
Saleh Mohammed Kayetbay ◽  
Mohammed A. Gepreel ◽  
Ahmed Mohamed El-Assal
Keyword(s):  
Magnetic Properties ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Stoichiometric Composition ◽  
Hydraulic Press ◽  
Ferromagnetic Shape Memory Alloys ◽  
Xrd Pattern ◽  
High Frequencies ◽  
Ferromagnetic Shape Memory

Shape memory alloys are programmed to memorize original trained shape. Ni-Mn-Ga is one of the ferromagnetic shape memory alloys. It is used as actuator, and sensor due to large output strain at high frequencies. This work presents a study on enhancing magnetic properties of thermally treated alloy by using new method of training in which alloys are exposed to different hydrostatic pressures using pressing die. Single near stoichiometric composition was produced. Elemental analysis showed homogeneity of the alloy. XRD pattern revealed Martensitic phase peaks. Transformation temperature was found to be below 100 OC. Training was applied by hydrostatic pressing die. Different training pressures were obtained using hydraulic press. After applying hydrostatic pressures starting from 2.5 bar to 10 bar, it was found that pressures up to 7.5 bar will increase the coercivity and saturation magnetization of the alloy, while pressures beyond 7.5 bar lessened these magnetic properties.

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