PENGARUH TEMPERATUR SINTERING TERHADAP SIFAT FISIS, MAGNET DAN MIKROSTRUKTUR DARI BaFe12O19 DENGAN ADITIF Al2O3
ABSTRAK
Telah diakukan pembuatan magnet permanen BaFe12O19 yang ditambahkan aditif
Al2O3 dengan variasi komposisi 1 dan 3 (%wt) mengggunakan metode mechanical
alloying dengan milling time 48 jam. Serbuk tersebut kemudian ditambahkan bahan perekat Poly Vinyl Alcohol (PVA) dan dicetak kering dengan tekanan 30 kg/cm2 (8 kG). Hasil cetakan berupa pelet dengan diameter rata-rata 20 mm x 3 mm. Selanjutnya dilakukan proses sintering dengan menggunakan vacuum furnace pada suhu 8000C, 9000C, 10000C, dan 1100oC yang ditahan selama 2 jam. Sampel yang telah disintering kemudian dikarakterisasi sifat fisis (bulk density, porositas, Linear Shrinkage), dianalisis struktur kristalnya dengan XRD dan Optical Microscope (OM), dimagnetisasi dan diukur kurva histerisisnya. Karakterisasi yang dilakukan meliputi sifat fisis yaitu densitas , porositas, dan Linear Shrinkage dengan metode Archimedes, dan analisa mikro struktur dengan menggunakan XRD dan OM. Sedangkan untuk analisis sifat magnet dengan menggunakan hasil pengukuran permagraph yang telah dimagnetisasi dengan Gaussmeter. Dari hasil pengukuran densitas dan porositas magnet BaFe12O19 dengan aditif Al2O3 menunjukkan bahwa nilai densitas cenderung
meningkat, porositas menurun sebanding dengan jumlah aditif Al2O3, dan Linear
Shrinkage meningkat. Dari hasil karakterisasi fisis diperoleh hasil yang terbaik yaitu pada milling time 48 jam dengan suhu 11000C pada komposisi 3 %wt, dengan nilai bulk density = 4,90 gr/cm3, porositas = 20,55%, dan Linear Shrinkage = 10,51%. Dari salah satu hasil analisa XRD menunjukkan bahwa telah terbentuk struktur kristal BaFe12O19 dan BaAlFe11O19, grainsize 15,7, memiliki Br = 3,22 kG dan Hc = 4.013
kOe.
Kata Kunci: Magnet permanen, BaFe12O19, Aditif Al2O3, Sintering
EFFECT ON SINTERING TEMPERATURE PHYSICAL PROPERTIES, MAGNET AND MICROSTRUCTURE OF Al2O3 BaFe12O19 WITH ADDITIVES
ABSTRACT
Has waged manufacture permanent magnets BaFe12O19 with Al2O3 additive is added to
the composition variation 1 and 3 (wt%) use traditional methods of mechanical alloying by milling time of 48 hours. The powder is then added to the adhesive Poly Vinyl Alcohol (PVA) and dry printed with a pressure of 30 kg / cm2 (8 kG). The printed form of pellets with an average diameter of 20 mm x 3 mm. Sintering process is then performed using a vacuum furnace at a temperature of 8000C, 9000C, 10000C, and 11000C were held for 2 hours. Samples were then characterized sintering physical properties (bulk density, porosity, Linear Shrinkage), analyzed the crystal structure by XRD and Optical Microscope (OM), magnetized and measured curves histerisisnya. Characterization was conducted on the physical properties, namely density, porosity, and Linear Shrinkage by Archimedes method, and a micro-structure analysis using XRD and OM. As for the analysis of magnetic properties using permagraph measurement results that have been magnetized by the Gaussmeter. From the results of measurements of density and porosity magnet BaFe12O19 with Al2O3 additive shows
that the density values tend to increase, the porosity decreases in proportion to the amount of additive Al2O3, and Linear shrinkage increases. From the results of the
physical characterization is obtained the best results in milling time of 48 hours at a temperature of 11000C at 3% wt composition, with a bulk density = 4.90 g / cm3, porosity = 20.55%, and 10.51% Linear Shrinkage, From one of the results of XRD analysis showed that the crystal structure has been formed BaFe12O19 and
BaAlFe11O19, grainsize 15.7, has Br = 3.22 kG and Hc = 4.013 Koe.
Keywords: Permanent Magnet, BaFe12O19, Additive Al2O3, Sintering
