| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
Experiment were carried out to investigate the effect of Na_2O, Li_2O, BaO and SrO additive on the magnetic and physical properites of SrZn_2-W and BaZn_2-W type hexagonal ferrite. The specimens were prepared by the conventional manufacturing methods without atmosphere control. It was found that the magnetic properties of SrZn_2-W ferrite are considerably improved on adding Na_2O and SrO after semisintering treatment. In BaZn_2-W type hexagonal ferrite, Li_2O and BaO complex addition is effective. The optimum condition of making magnet with suitable properties are as follows : chemical analysis composition : Sr^2+_53Zn^2+_95Na^+_71Fe^2+_80Fe^3+_<157>O_<27> ; semisintering condition : 1300ﾟC x 1h in air, sintering condition : 1225ﾟC x 0.5h in air. The magnetic properties are : J_m=0.415T, J_r=.375T, H_<cJ>=123.4kA/m, H_<cB>=118.6kA/m, (BH)_<max>=22.8kJ/m3, T_c=361ﾟC, H_A=1084kA/m, K_A=2.25 x10^5 J/m^3 and n_B=33.8muB.
The fine powders for bonded magnets was made by semisintered SrO・2ZnO・nFe_2O_3(n=7-9) compounds using planetary ball mill. As a result, in SrO・2ZnO・7Fe_2O_3 compound the value of coercive force is obtained 180kA/m. It was found that these powders can use for bonded magnet powder.
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