SUPER LOW CORE-LOSS SOFT MAGNETIC MATERIALS BY P/M METHOD

摘要

The remarkable advances have been realized in the AC soft magnetic material for electronics and automotive parts, by the powder metallurgy method using iron-based powder covered with insulated layers. In order to applied this material to motor cores, iron loss of the compaction must be reduced below W_(10/1k) < 100W/kg, less than the typical iron loss of 0.35mm-thick flat rolled soft magnetic laminated steel sheets. In order to reduce the total iron loss, soft magnetic powders and insulation layer covered over each powder was improved. To use high purity iron powders (impurity content < 200ppm) and insulation layer with good heat resistance (over 773 K) was turned out to be effective for making iron loss lower. Advanced material showed W_(10/1k) = 68 W/kg. This material shows superiority over the conventional laminated steel sheets at the frequency range over 300Hz.