Shrinkage, Density and Hardness of Hard Magnetic Material (BaFe12O19) Based on Iron Sand Produced by Conventional Solid-State Reaction Process

This paper presents shrinkage, density and hardness number of hard magnetic (BaFe 12 O 19 ) based on iron sand produced by conventional solid-state reaction process. Iron sand was mechanically filtered using permanent magnets 35 times. The filtered iron sand was heated at temperatures of 900°C for 5 hours in the furnace and after it was cold and produce Fe 2 O 3 phase. Powders of Fe 2 O 3 and BaCO 3 were mixed and milled in a shaker ball mill up to 3 hours. The powder mixture compacted at a pressure of 2.5, 5 and 7.5 tons and followed by sintering at temparature of 1100, 1150 and 1200°C for 1 hour in the furnace. Shrinkage measurements include diameter and height uses vernier caliper, while density measurements use the Archimedes method. Hardness number obtained with pass vickers hardness testing methods. Barium ferrite ‘s maximum shrinkage and bulk density values were at 7.5 tons compacting pressure and 1200°C sintering temperature where the shrinkage value was 7.44 percent, average shrinkage was 3.49 percent, and density was 4.397 g/cm 3 . In barium ferrite with a compacting pressure of 7.5 tons and a sintering temperature of 1200 °C which is equivalent to 741 HV the highest hardness value is found. The higher the compacting press and sintering temperature, the greater the importance of bulk density and hardness of the materials.