Study of Particle Size and Affix Fe in Permanent Magnet Materials BaFe 12 O 19 against Their Physical Properties

Abstract

Research on the addition affixes Fe to a permanent magnet material of barium hexaferrite (BaFe 12 O 19 ) has been done. Wet and dry milling were applied to the BaFe 12 O 19 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/cm 3 . The milling time is inversely to particle size and directly proportional to true density. The optimum condition of making a permanent magnet sample of BaFe 12 O 19 was reached on the addition of 1% Fe and sintering temperature 1150°C, generating porosity = 0.065%, bulk density = 4.89 g/cm 3 , 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.