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.

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.

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 EFFECT OF Mn AND Ti ADDITION ON THE CRYSTALLOGRAPHIC STRUCTURE AND MAGNETIC PROPERTIES OF SrFe12O19

2020 ◽  
Vol 82 (4) ◽  
Author(s):  
Wisnu Ari Adi ◽  
Yunasfi Yunasfi ◽  
Yosef Sarwanto ◽  
Muhammad Aziz Majidi
Keyword(s):  
Magnetic Properties ◽  
Raw Materials ◽  
Site Occupancy ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
Total Magnetization ◽  
Multi Phase ◽  
Ti Addition

The synthesis and characterization of composition SrFe12-(x+y)MnxTiyO19 (x = y and x ≠ y) compound by using solid state reaction have been performed. The raw materials were SrCO3, Fe2O3, MnCO3, and TiO2. The mixed powder was compacted at 5000 psi into pellets and sintered at 1050°C in the air at atmosphere pressure for 15 hours and furnace cooling. The refinement results of x-ray diffraction pattern show that the doping composition (x = y) was a single phase while the doping composition (x ≠ y) was multi phase. We concluded that effect of substitution upon magnetic properties revealed that total magnetization, remanence and coercivity changed with substitution due to preferential site occupancy of substituted Mn2+ and Ti4+ ions. The coercivity decreases with increase in Mn and Ti concentration. This effect is related with Fe3+ magnetic moment changes after they have already substituted Mn2+ and Ti4+ ions. Since the coercivity and total magnetization may be controlled by substitution while maintaining resistive properties, making this material useful for microwave absorber. 

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

Quasi-static crack propagation in Ti-6Al-4V in inert and aggressive media

2019 ◽  
Vol 37 (5) ◽  
pp. 533-538
Author(s):  
Sergio Baragetti ◽  
Emanuele Borzini ◽  
Emanuele Vincenzo Arcieri
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Static Loading ◽  
Weight Ratio ◽  
High Strength ◽  
Surface Oxide Film ◽  
Notch Geometry ◽  
Consequent Reduction ◽  
Corrosive Environments

AbstractHigh strength-to-weight ratio Ti-6Al-4V alloy is used in many engineering applications. Its surface oxide film can protect the substrate from interaction with a lot of corrosive environments. Unfortunately, this surface layer can be damaged under mechanical and chemical actions with a consequent reduction in corrosion resistance. A characterization of the untreated alloy under quasi-static loading is here provided. Inert and aggressive environments have been investigated and the influence of the notch geometry of the alloy has also been analyzed.

scholarly journals Evaluation of Kalalani vermiculite for production of high strength porcelain insulators

2019 ◽  
Vol 51 (2) ◽  
pp. 223-232 ◽  
Author(s):  
Blasius Ngayakamo ◽  
Eugene Park
Keyword(s):  
Water Absorption ◽  
Bulk Density ◽  
Bending Strength ◽  
Raw Materials ◽  
High Strength ◽  
Microstructural Characterization ◽  
Dielectric Strength ◽  
Raw Material ◽  
Porcelain Insulators

The present work has evaluated Kalalani vermiculite as a potential raw material for the production of high strength porcelain insulators. Three porcelain compositions were prepared to contain 0, 20 and 30 wt% of Kalalani vermiculite. Porcelain samples were fabricated using a semi-drying method. The chemical, mineralogical phases and microstructural characterization of the raw materials were carried out using XRF, XRD, and SEM techniques, respectively. Water absorption, bulk density, dielectric and bending strengths were performed on porcelain samples fired up to 1300?C. However, at the sintering temperature of 1250?C, the porcelain sample with 20 wt% of Kalalani vermiculite gave the dielectric strength of 61.3 kV/mm, bending strength of 30.54 MPa, bulk density of 2.21 g/cm3 and low water absorption value of 0.21 % which is the prerequisite properties for high strength porcelain insulators. It was therefore concluded that Kalalani vermiculite has the potential to be used for the production of high strength porcelain insulators

Preparation Process Optimization and Characterization of an Ultra-Hard Al-Mg-B Material

2009 ◽  
Vol 79-82 ◽  
pp. 279-282
Author(s):  
Gang Feng ◽  
Lin Zhang ◽  
Guang Hui Min
Keyword(s):  
Bending Strength ◽  
Raw Materials ◽  
Weight Ratio ◽  
Sintered Body ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sinter Method ◽  
The Matrix ◽  
Metal Borides

The Al-Mg-B polycrystalline bodies were prepared using vacuum hot-pressing sinter method by pure Al, Mg and B powders. Process parameters and constitution variation were investigated to obtain compact Al-Mg-B sintered body with high mechanical properties. Al-13%Mg-72.7%B(weight ratio) sintered body prepared under 1600°C, 30MPa for 1 hour in vacuum was proved to be optimum, which bending strength was 156MPa and Vickers hardness was 2220. X-ray diffraction (XRD), Micron Probe Micro-analyzer (EPMA) were employed to analyse the ultimate phases. The results showed that the matrix phases were metal borides including AlB12, MgB6 and AlMgB14, while Al2O3 and MgAl2O4 phases existed which connected or filled in the matrix grains to promote the compactness degree, where oxygen introduced from impurities in raw materials. A portion of Mg in AlMgB14 combined with oxygen during heating to 1600°C which helped to form MgAl2O4 and AlB12 in the end.

scholarly journals KARAKTERISASI BESARAN MAGNET PERMANEN DARI HASIL CAMPURAN NdFeB DAN SERBUK EPOXY RESIN

2020 ◽  
Vol 22 (2) ◽  
Author(s):  
Herawati Herawati ◽  
Asep Yuyu
Keyword(s):  
Epoxy Resin ◽  
Permanent Magnets ◽  
Raw Materials ◽  
Atomic Ratio ◽  
Hydraulic Press ◽  
Raw Material ◽  
Cylindrical Shape ◽  
Dc Motors ◽  
Composition Variation ◽  
Sample Test

The bonded permanent magnet Nd 2 Fe 14 B has been made using raw materials Nd-Fe-B powder mixed withadhesive epoxy resin . Permanent magnets can be applied as a component of small DC motors and car parts.NdFeB composition variation on epoxy resins are made with the ratio of 93 : 7, 95 : 5, 90 : 10, 80 : 20, 70 : 30, 60: 40, 50 : 50, (% weight). Raw material NdFeB was made from the mixture of Nd, Fe and B with atomic ratio 2 :14 : 1 by using mechanical alloying technique. The blend of NdFeB and epoxy resin has been done in the vacuumbox . Sample test was prepared by compression with hydraulic press pressure 100kg/cm 2 within 2 minutes. Heattreatment in the oven with a temperature of 180 O C for 4 hours. The sample test was made in cylindrical shape witha diameter of 2-3 cm and thickness of 0.4 to 0.9 cm. The measurement of density vs. Histerisis has been recorded.The results show that the bonded NdFeB permanent magnets achieve optimum conditions in comparison NdFeB97% and 3% epoxy with the density = 4.49 g/cm3 and remanansi (Br) = 5.32 kG, HcJ = 7.936 kOe and (BH) max= 5.75 MGOe.

Synthesis and Characterization of Mg-Al Layered Double Hydroxide

2012 ◽  
Vol 454 ◽  
pp. 101-104 ◽  
Author(s):  
Wan Zhong Yin ◽  
Qi Tan ◽  
Lei Liu ◽  
Xiao Li Li
Keyword(s):  
Layered Double Hydroxide ◽  
Milling Time ◽  
Raw Materials ◽  
Weight Ratio ◽  
Hydroxyl Groups ◽  
Wet Milling ◽  
Ft Ir ◽  
Double Hydroxide ◽  
Partical Size

Mg-Al layered double hydroxide was synthesized by the method of mechanochemistry /crystallization at the dry milling time of 6 h, wet milling time of 2 h, milling speed of 250 r/min, and ball to powder weight ratio of 50 to 1 using brucite, Al(OH)3 and Na2CO3 as the raw materials. Characterizations of the materials were achieved by XRD, TEM, FT-IR and TG-DSC. The results showed that well crystallized Mg-Al LDH with average partical size of 40 nm were synthesized under this condition. Mg-Al LDH was formed with CO32- freely intercalated between the hydroxide host layers. The material generally decomposed via two distinct stages. The first stage at 229.5 °C was attributed to the loss of interlayer water, and the second stage at 407.8°C was due to the loss of hydroxyl groups from the brucite-like layer, as well as of the carbonate irons.

Synthesis and Characterization of TiC Powders by Carbothermal Reduction Method in Vacuum

2015 ◽  
Vol 1089 ◽  
pp. 147-151
Author(s):  
Hong Yan Sun ◽  
Xin Kong ◽  
Wei Sen ◽  
Gui Yang Liu ◽  
Zhong Zhou Yi
Keyword(s):  
Corrosion Resistance ◽  
Titanium Dioxide ◽  
Titanium Carbide ◽  
Carbothermal Reduction ◽  
Raw Materials ◽  
Acid Corrosion ◽  
Mixed Solution ◽  
Air Atmosphere ◽  
Lower Valence

TiC powders have been prepared with titanium dioxide and charcoal powders as raw materials by vacuum carbothermal reduction technique. Meanwhile the as-prepared TiC powders were characterized by acid corrosion resistance test and oxidizability test. The results show as follows: the acid corrosion resistance of titanium carbide powders prepared at the optimum experiment conditions is better than that of industrial powders. It hardly dissolves in HCl, H2SO4, HNO3, HF, HClO4and aqua regia, and slightly dissolves in mixed solution HF+HNO3. The TiC powders are gradually oxidized at 352°C~917°C at air atmosphere and the product may be titanium dioxide and titanium oxides with lower valence. When the temperature rises to 546°C, a large quantity of titanium carbide powders are oxidized. And when the temperature rises to 688°C, besides the titanium carbide powders are oxidized to release heat, the free carbon is also oxidized and transformed into CO2gas to escape.

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