Abstract
Sr-La-Co M-type ferrite fine particles were prepared by mechanical compounding using the planetary ball-mill which was followed by heat treatment. This experiment was carried out to investigate the effect of CaO and SiO2 additives on the magnetic properties of anisotropic sintered magnets using Sr-La-Co ferrite fine particles by mechanical compounding method. The optimum conditions for making Sr-La-Co system anisotropic sintered magnets and some properties of typical specimens are as follows. Chemical composition: SrO·6.3Fe2O3 added with 2wt%La2O3 and 0.3wt%Co3O4; planetary ball-mill condition: 300 rpm × 1h; heat treatment condition: 1200°C × 4h in air, additives: 1.3wt%CaO and 0.5wt%SiO2; pressing condition: 98MPa in 800kA/m magnetic field; sintering conditions: 1170°C × 2 h; magnetic and physical properties are Jr = 0.42 T, HcJ=171 kA/m, HcB =169kA/m, (BH)max=33.7kJ/m3, Tc=453.2°C, and D=4.88 Mg/m3.
