Study of Particle Size and Affix Fe in Permanent Magnet Materials BaFe12O19 against Their Physical Properties

Abstract

Research on the addition affixes Fe to a permanent magnet material of barium hexaferrite (BaFe12O19) has been done. Wet and dry milling were applied to the BaFe12O19 powder using high energy milling, where milling time are 0, 10, 20 and 40 hours. Variations the addition affixes Fe are 1, 5, 10 and 20% of weight with sintering temperature: 1100, 1150 and 1200°C. Each temperature was hold for 1 hour. Average particle size, true density, porosity, bulk density and magnetic flux density of the sample of BaFe12O19 are observed parameters. The results showed that particle size decreased by 64.67% after 20 hours of milling from 21.4 μm to 7.56 μm. Before and after 20 hours of milling, true density also increase from 4.61 to 4.70 g/cm3. The milling time is inversely to particle size and directly proportional to true density. The optimum condition of making a permanent magnet sample of BaFe12O19 was reached on the addition of 1% Fe and sintering temperature 1150°C, generating porosity = 0.065%, bulk density = 4.89 g/cm3, and the magnetic flux density = 883.3 Gauss. Increasing of Fe and sintering temperature tends to increase the number of pores and magnification of particle size on the sample.