POWDER-COMPACT MAGNETIC CORE, POWDER FOR MAGNETIC CORE, AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a powder-compact magnetic core superior in specific resistance and strength.SOLUTION: A method for manufacturing powder for a magnetic core which is used for manufacturing a powder-compact magnetic core comprises: a non-oxidizing processing step for producing insulator-coated particles with their surfaces at least partially covered by an insulator layer made of an aluminum oxide by heating oxidized particles including soft magnetic particles of an iron alloy including Al and Si, and an iron oxide near the surfaces of the soft magnetic particles in a non-oxidizing atmosphere. Using powder for a magnetic core including the insulator-coated particles thus produced, a powder-compact magnetic core having a high specific resistance and a high strength can be obtained. The oxidized particles are produced by an oxidizing processing step for heating the soft magnetic particles in an oxidizing atmosphere. Also, such powder-compact magnetic core having a high specific resistance and a high strength can be obtained by performing a powder-compact heating step for heating a powder compact formed by the oxidized particles in a non-oxidizing atmosphere.