Pengaruh Komposisi BaFe12O19 dan Fe pada Pembuatan Hybrid Bonded Magnet Berbasis NdFeB terhadap Sifat Fisis, Magnet dan Mikrostruktur

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iv

PENGARUH KOMPOSISI BaFe

12

O

19

dan Fe pada PEMBUATAN

HYBRID BONDED MAGNET

BERBASIS NdFeB

terhadap SIFAT

FISIS, MAGNET dan MIKROSTRUKTUR

ABSTRAK

Telah dilakukan pembuatan hybrid bonded magnet permanen berbasis NdFeB yang ditambahkan dengan 2 %wt serbuk besi dan BaFe12O19 dengan variasi komposisi (x = 5, 10, 15, dan 20 % wt). Proses preparasi bahan baku mulai dari pencampuran serbuk NdFeB tipe MQP-B+ dengan BaFe12O19 dan serbuk Fe, digerus dan dicampur bahan perekat Exopy Resin sebanyak 6 %wt dan dicetak dengan gaya 8 tonf sehingga membentuk pellet dengan diameter 18,5 mm dan tebal 4,3 mm. Sampel yang telah dicetak kemudian dikeringkan menggunakan Under Vacuum Dryer dengan temperatur 80°C dengan tekanan 15 mbar ditahan selama 1 jam. Karakterisasi yang diuji meliputi sifat fisis (densitas, kekerasan dan laju korosi), mikrostruktur menggunakan Optical Microscope dan sifat magnet dengan menggunakan Vibrating Sample Magnetometer. Dari hasil pengukuran densitas dan kekerasan hybrid bonded magnet menunjukkan bahwa nilai densitas cenderung menurun dan kekerasan cenderung meningkat sebanding dengan jumlah penambahan BaFe12O19. Kondisi optimum dicapai pada penambahan (x = 5 %) BaFe12O19 menghasilkan densitas = 4,469 × 103 kg/m3 dan laju korosi 8,268 × 10-3 m/tahun. Nilai kekerasan optimum dihasilkan oleh sampel dengan penambahan (x = 10%) BaFe12O19 dan penambahan 2% Fe dengan nilai 8,27 × 108 N/m2. Sifat magnet dengan penambahan (x = 5 %) Ba.Fe12O19 disertai penambahan Fe maupun tanpa Fe dapat diketahui nilai induksi remanen magnetik (Br) = 362,9 mT dan 382,7 mT, koersivitas (HcJ) = 684,6 kA/m dan 710,2 kA/m dan energi produk (BH)max = 24,096 kJ/m3 dan 22,655 kJ/m3 dengan nilai fluks magnetik = 97,32 mT dan 102,985

mT. Pengaruh panambahan komposisi BaFe12O19 cenderung menurunkan nilai densitas

dan sifat magnetnya namun meningkatkan nilai kekerasannya.

Kata Kunci : BaFe12O19, Hybrid Bonded Magnet, NdFeB, Serbuk Fe, Sifat Magnet.

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v

EFFECT OF BaFe

12

O

19

and Fe ADDITION in MANUFACTURE of

HYBRID BONDED MAGNET BASED of NdFeB

on PHYSICAL,

MAGNETIC PROPERTIES and MICROSTRUCTURE

ABSTRACT

Hybrid Bonded permanent magnet with addition of BaFe12O19 and 2 %wt Fe

Powder has been done with the variation composition (x = 5, 10, 15 and 20% wt). The preparation process started by mixing NdFeB MQP-B+ powder with BaFe12O19

and Fe Powder then mixed with 6 % wt adhesive Epoxy Resin and compacted with a pressure of 8 tonf to form a pellet with diameter of 18,5 mm and thickness of 4,3 mm. Samples which have been pressed, then dryed using Under Vacuum Dryer with a heating temperature 80°C and pressure 15 mbar held for 1 hours. The characterizations was conducted on the physical properties, such as density by using dimension method and hardness by using Vickers, microstructure analysis using OM, and magnetic properties with vibrating sample magnetometer. Based on the density and hardness measurement, it can be concluded that hybrid bonded magnet has density that tend to decrease and hardness tend to increase as the increasing of composition BaFe12O19. The optimum condition is achieved at a value of x = 5%,

where the density value = 4,469 × 103 kg/m3 and corrosion rate = 8,268 × 10-3 m/year. Optimum hardness value is at addition of (x = 10%) BaFe12O19 with 2% Fe addition

reach 8,27 × 108 N/m2. The hysteresis curves for Fe and non Fe addition show that values of the remanent induction (Br) = 362,9 mT and 382,7 mT, coercivity (HcJ) =

684,6 kA/m and 710,2 kA/m and the maximum energy product (BH)max = 24,096 kJ/m3

and 22,655 kJ/m3 with magnetic flux value = 97,32 mT dan 102,985 mT. Effect of increasing composition of Ba.Fe12O19 is tend to decrease density values, and magnetic

properties but increase its hardness value.

Keywords : BaFe12O19, NdFeB, Fe Powder, Hybrid Bonded Magnet, Magnetic

Properties.

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