焼鈍した扁平純鉄粉による圧粉磁心の特性

To improve the properties of powder magnetic core for motors, such as iron loss, resistivity and strength, pure iron powder was deformed into flaky-shaped and then annealed to decrease strain by deformation. It was confirmed that the strength of iron core increased with increasing the aspect ratio of powder. However, the resistivity extremely decreased. The iron core showed properties as follows; density = 7.66 × 106 g/m3, resistivity = 2.5 × 104 μΩ·m, iron loss (Bmax = 1 T, f = 400 Hz) = 30 W/kg, iron loss (Bmax = 1 T, f = 800 Hz) = 63 W/kg, B5k = 1.49 T, radial crushing strength = 95 MPa. Especially, eddy current loss coefficient was 0.008 mWs2/kg, extremely lower than electromagnetic steel sheet and powder magnetic core reported ever.