| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing powder for a sendust core capable of obtaining a core small in core loss in the case it is formed into a product. SOLUTION: A sendust alloy melt having a compsn. of 4 to 13% Si, 4 to 7% Al, and the balance Fe is prepd. in an inert atmosphere. The flow of the sendust alloy melt is sprayed with water under 1500 to 3500 psi via>=4 pieces of nozzles having 10 to 20mm diameter to form powder having an approximately regular polygonal shape. The powder is mixed with 0.1 to 1.0% kaolin powder and is thereafter subjected to heat treatment for>=30min in the temp. range of 700 to 850 deg.C in a reducing atmosphere. The heat-treated powder is coated with composite ceramic contg. magnesia, kaolin and water glass and in which specific resistance after firing at 700 deg.C for 1 hr is regulated to 200×10<6> MΩ.cm and density is regulated to 2.3 to 3.0g/cm<3> by 0.5 to 5% to the powder weight by a wet coating method.
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