Bonded Magnet Permanen Nd2Fe14B dengan Perekat  Silicone Rubber dan Karakterisasinya

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

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Properties of Silicone Rubber-Based Composites Reinforced with Few-Layer Graphene and Iron Oxide or Titanium Dioxide

Polymers ◽

10.3390/polym13101550 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1550

Author(s):

Vineet Kumar ◽

Anuj Kumar ◽

Minseok Song ◽

Dong-Joo Lee ◽

Sung-Soo Han ◽

...

Keyword(s):

Magnetic Properties ◽

Titanium Dioxide ◽

Iron Oxide ◽

Stress Relaxation ◽

Silicone Rubber ◽

Room Temperature ◽

Relaxation Rates ◽

Layer Graphene ◽

Few Layer Graphene ◽

Mechanical Actuation

The increasing demand for polymer composites with novel or improved properties requires novel fillers. To meet the challenges posed, nanofillers such as graphene, carbon nanotubes, and titanium dioxide (TiO2) have been used. In the present work, few-layer graphene (FLG) and iron oxide (Fe3O4) or TiO2 were used as fillers in a room-temperature-vulcanized (RTV) silicone rubber (SR) matrix. Composites were prepared by mixing RTV-SR with nanofillers and then kept for vulcanization at room temperature for 24 h. The RTV-SR composites obtained were characterized with respect to their mechanical, actuation, and magnetic properties. Fourier-transform infrared spectroscopy (FTIR) analysis was performed to investigate the composite raw materials and finished composites, and X-ray photoelectron spectroscopy (XPS) analysis was used to study composite surface elemental compositions. Results showed that mechanical properties were improved by adding fillers, and actuation displacements were dependent on the type of nanofiller used and the applied voltage. Magnetic stress-relaxation also increased with filler amount and stress-relaxation rates decreased when a magnetic field was applied parallel to the deformation axes. Thus, this study showed that the inclusion of iron oxide (Fe3O4) or TiO2 fillers in RTV-SR improves mechanical, actuation, and magnetic properties.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.855.28 ◽

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.

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.855.34 ◽

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.

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Preparation of Strontium Ferrite Powders by Mechanochemical Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.1736 ◽

2011 ◽

Vol 110-116 ◽

pp. 1736-1740 ◽

Cited By ~ 1

Author(s):

Ju Hua Luo

Keyword(s):

Magnetic Properties ◽

Room Temperature ◽

Single Phase ◽

Raw Materials ◽

X Ray Diffraction ◽

X Ray ◽

Starting Mixture ◽

Ft Ir ◽

Mechanochemical Treatments ◽

Firing Method

Sr-ferrite powders were preparated by mechanochemical treatments using SrCO3 and Fe2O3 as raw materials. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometry (VSM) were employed to evaluated the morphologies, structures and magnetic properties of samples. The results indicated that the starting mixture became amorphous stage after ball-milled for 30h, and single phase SrFe12O19 could be obtained after annealed at 900°C for 2h. And the saturation magnetization was 58.2Am2/kg, and coercivity was 281.2 kA/m at room temperature. In comparison with the traditional firing method , the mechanochemical method benefited achieving the higher coercivity, which indicated that the samples had a better magnetic properties.

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An Improvement on Tracking Resistance of Silicone Rubber Filled with Micro-Wollastonite/Gehlenite Synthesized by Solid-State Reaction

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.902.107 ◽

2021 ◽

Vol 902 ◽

pp. 107-111

Author(s):

Pattarabordee Khaigunha ◽

Tanakorn Wongwuttanasatian

Keyword(s):

Silicone Rubber ◽

Room Temperature ◽

Raw Materials ◽

Filler Loading ◽

Test Method ◽

X Ray Diffraction ◽

X Ray ◽

Surface Tracking ◽

Long Time ◽

Scanning Electron

Enhancement of the room temperature vulcanization silicone rubber (RTV) tracking resistance with various filler loadings of synthesized wollastonite against electrical surface tracking was prepared. The X-ray diffraction (XRD), Scanning electron microscope (SEM), and X-ray fluorescent (XRF) techniques were involved in characterizing the synthesized substances. The test method IEC-60587 standard was employed to evaluate the surface tracking resistance. The results obtained from the XRF technique confirmed that the raw materials could be synthesized for wollastonite, while the XRD and SEM techniques revealed the formation of wollastonite (CaSiO3) associated with gehlenite (Ca2Al2SiO7). Moreover, it was found that the electrical surface tracking resistance of composite insulation takes a long time to track when the filler loading is increased more than 5 phr.

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Transforming a Diamagnetic Ordered Mesoporous Silica Monolith into a Room Temperature Permanent Magnet through Multiscale Control of the Magnetic Properties

ChemNanoMat ◽

10.1002/cnma.201800333 ◽

2018 ◽

Vol 4 (12) ◽

pp. 1254-1261 ◽

Cited By ~ 1

Author(s):

Virgile Trannoy ◽

Laura Altenschmidt ◽

Giulia Fornasieri ◽

Amélie Bordage ◽

Eric Rivière ◽

...

Keyword(s):

Magnetic Properties ◽

Mesoporous Silica ◽

Permanent Magnet ◽

Room Temperature ◽

Ordered Mesoporous Silica ◽

Silica Monolith ◽

Ordered Mesoporous

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Fabrication and Properties of Al2O3-SiC/Sialon Composite Refractories

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.512-515.908 ◽

2012 ◽

Vol 512-515 ◽

pp. 908-911

Author(s):

Ding Yun Ye ◽

Yan Gai Liu ◽

Zhao Hui Huang ◽

Ming Hao Fang ◽

Yang Yang Liu

Keyword(s):

Water Absorption ◽

Bulk Density ◽

Carbothermal Reduction ◽

Room Temperature ◽

Bending Strength ◽

Raw Materials ◽

Apparent Porosity ◽

Low Grade ◽

Sialon Powder ◽

Aluminate Cement

Sialon powder was synthesized using low grade bauxite as raw materials by carbothermal reduction-nitridation reaction. The influence of synthesizing temperatures (1300°C, 1350°C, 1400°C, 1450°C, 1500°C and 1550°C) on the phases of the final products was studied by XRD technique. β-Sialon (Z=3) formed at 1350°C and decreased when the temperature was higher than 1450°C. The optimizing reaction temperature for preparing Sialon was 1450°C. The Al2O3-SiC/Sialon composite refractories were prepared at 200°C, 400°C and 600°C for 24h with white corundum, brown corundum, SiC, Sialon powders prepared at 1450°C and calcium aluminate cement. The bulk density, apparent porosity, water absorption and bending strength of the Al2O3-SiC/Sialon composite refractories at room temperature were studied. The results show that the bulk density decreased and then increased with the enhancing of the temperature and reached the highest value of 2.43g/cm3 at 200°C. The apparent porosity and water absorption reached the lowest values of 26.68% and 10.99% at 200°C respectively. The bending strength decreased as the temperature increased, reached the highest value of 0.73MPa at 200°C.

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Nickel Ferrite Nanocrystallites Synthesized by Sol-Gel and Coprecipitation Methods: A Comparative Study

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.305 ◽

2009 ◽

Vol 79-82 ◽

pp. 305-308 ◽

Cited By ~ 2

Author(s):

Ming Wei Li ◽

Cui Ping Liu ◽

Xiao Mei Gao

Keyword(s):

Magnetic Properties ◽

Comparative Study ◽

Calcination Temperature ◽

Nickel Ferrite ◽

Room Temperature ◽

Raw Materials ◽

Sol Gel ◽

Nucleation And Growth ◽

Washing Process ◽

Superparamagnetic Properties

The microstructures and magnetic properties of nickel ferrite synthesized by coprecipitation and sol–gel methods are comparatively studied. The coprecipitation-derived samples have Fe/Ni ratios differing from their raw materials because of the precipitation washing process. The stoichiometric metal cations (Fe/Ni=2.0) in the xerogel facilitated the nucleation and growth of nickel ferrite nanocrystallites at lower calcination temperature in sol–gel method. The samples consist of nickel ferrite nanocrystallites, and have superparamagnetic properties at room temperature.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.864.65 ◽

2016 ◽

Vol 864 ◽

pp. 65-69 ◽

Cited By ~ 1

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.

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