Pengaruh Waktu Dry Milling Terhadap Karakteristik Dan Sifat Magnet Permanen Nd-Fe-B

Abstract

` AbstrakTelah dilakukan proses penghalusan serpihan NdFeB dengan menggunakan metode dry milling dalam atmosfir gas inert dengan menggunakan gas Nitrogen (N2) dengan bahan awal yang digunakan berupa serpihan NdFeB dengan waktu milling yang divariasikan selama 8 jam, 16 jam, 24 jam dan 48 jam. Besaran magnetik yang diukur adalah koersivitas (Hc), induksi remanensi magnetik (Br) dan energi produk maksimum (BHmaks). Proses preparasi sampel dimulai dengan penghalusan serpihan dengan berbagai variasi waktu milling, dicetak dengan gaya 7 tonf selama 2 menit, dan dengan ditambahkan bahan perekat celuna sebanyak 3 wt%, hingga membentuk pelet dengan diameter ±1,6 cm. Selanjutnya sampel pelet di heat treatment selama 1 jam pada suhu 170ᵒC dan setelah itu dilakukan coating pada sampel. Sampel pelet yang telah melalui proses heat treatment, dimagnetisasi dengan impulse magnetizer pada tegangan 1500V DC. Sampel pelet yang telah dimagnetisasi diukur fluks density menggunakan Gaussmeter. Dari nilai densitas fluks magnet sampel, diperoleh sampel terbaik yaitu sampel hasil milling selama 48 jam pada suhu heat treatment 170ᵒC dan diperoleh fluks magnet sebesar 485,8 Gauss. Koersivitas pelet NdFeB yaitu 1,171 kOe dan BHmaks sebesar 0,62 MGOe. Kata-kata kunci: NdFeB, heat treatment, dry milling, gas inert AbstractParticle refining process of flakes NdFeB by dry milling method within an inert gas atmosphere using Nitrogen gas (N2) with based material was flakes NdFeB and with milling time parameters were variated for 8 hours, 16 hours, 24 hours and 48 hours had been done. The measured magnetic properties were coercivity (Hc), remanence (Br) and maximum energy product (BHmax). The preparation raw material process was started with particle refining with milling time variety, then it was pressed with 7 tonf force for 2 minutes and with added adhesive celuna as much as 3 wt% up to become pellets form with a diameter ±1.6 cm. Further the pellet samples were given heat treatment for 1 hour at temperature 170ᵒC and after that all the samples were coated. Pellet samples that have been done heat treatment, were magnetized with the impulse magnetizer in 1500V DC voltage. Pellet sample that had been magnetized ,its flux density was measured by using a Gaussmeter. From the magnetic flux density sample value, the best sample that obtained was the sample in milling time for 48 hours at heat treatment's temperature was 170ᵒC and obtained magnetic flux density at 485.8 Gauss. The NdFeB pellet coercivity was 1.171 kOe and the BHmax was 0.62 MGOe.

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

“…Metode dry milling dalam proses penggilingan menggunakan gas inert, ini bertujuan untuk mencegah terjadinya oksidasi lingkungan pada magnet dimana gas inert merupakan gas yang tidak reaktif atau tidak mudah bereaksi. Sedangkan metode Wet milling pada saat proses penggilingan menggunakan toluene untuk mencegah terjadinya proses oksidasi (korosi) pada NdFeB [6]- [8].…”

SYNTHESIS POLYMER MATRIX COMPOSITE EPOXY FeNdB-Cu FOR RADAR ABSORBER COATING APPLICATION

“…After the addition of Cu doping, there was a change in the magnetic value, there was a significant increase in the magnetic saturation to 5.22 kG. Increasing the saturation value in magnetic material results in an increase in the degree of magnetization, saturation magnetization is a state where the magnetic spins in the material are in the same direction as the external magnetic field [2] the more direction the magnetic domain in the material is, the more waves can be absorbed, thereby increasing the reflection loss value in PMC more than twice from -7.95 dB to -18.84 dB can be seen in Figure 7.…”

“…Three important characteristics that describe magnets performance is magnetic induction remanence (Br), Coercivity (Hc), and maximum energy product (BHmax). Permanent magnets Neodymium-Iron-Boron always attracts a lot of attention since founded in 1980 because of the performance [2]. With the consideration of NdFeB advantage, the research of this material needed to maximize.…”