公开(公告)号：DE102004055694A1

公开(公告)日：2005-07-07

申请号：DE102004055694

申请日：2004-11-18

Applicant: DENSO CORP

Inventor： NISHIJIMA YOSHIAKI ,  NOMURA YURIO ,  YAMAGUCHI KOUICHI ,  ISHIKAWA YUUICHI ,  HAYAMA HIDEKAZU

IPC: B22F9/08 ,  B22F1/02 ,  C23C8/18 ,  H01F1/12 ,  H01F1/20 ,  H01F1/33

Abstract: The invention provides a method for manufacturing a soft magnetic powder material covered by oxide layers at surfaces of the powder, by using a soft magnetic alloy powder containing a soft magnetic powder material and a second element such as Si having an oxidizing reactivity higher than iron, and heating the soft magnetic alloy powder in an atmosphere of a weak oxidizing gas by mixing a weak oxidizing gas in an inert gas, and oxidizing selectively the second element at surface layers of the powder while restraining an oxidation of iron to form thin oxide layers with high electrical resistance.