Pengaruh Komposisi Al2o3 Dan Milling Time Terhadap Sifat Fisis, Magnet Dan Mikrostruktur dari BaFe12O19

Abstract

Has waged manufacture permanent magnets BaFe12O19 with Al2O3 additive is added to the composition variation of 0, 1, 3, 5 and 7 (wt%) use traditional methods of mechanical alloying by milling time 12 and 36 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 1100oC were held for 2 hours. Samples were then characterized sintering physical properties (green body density, bulk density and porosity), analyzed the crystal structure by XRD and Optical Microscope (OM), magnetized and measured curves histerisisnya. Characterization was conducted on the physical properties, namely density and porosity by Archimedes method, and a micro-structure analysis using XRD and OM. As for the analysis of magnetic properties using permagraf 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 tends to decrease and the porosity increases in proportion to the amount of additive Al2O3. From the results of the physical characterization is obtained the best results in milling time of 36 hours with a composition of 0% wt (without additives), with the value of the green body density = 3.07 g / cm3 , bulk density = 5.06 g / cm3 and porosity = 4 , 62%. From one of the results of XRD analysis showed that the crystal structure has been formed BaFe12O19 and BaAlFe11O19, grainsize 15.6, has Br = 2.01 kG and Hc = 0.28 MGOe.