Title:
CORROSION-RESISTANT PERMANENT MAGNET
Document Type and Number:
Japanese Patent JP3234306
Kind Code:
B2
Abstract:
PURPOSE: To improve corrosion resistance of a corrosion-resistant permanent magnet by a method wherein a tin oxide coating layer is adhered on the surface of an Fe-B-Ra magnet body having a specified component by a thermal decomposition method using a tin alkoxide compound solution.
CONSTITUTION: A corrosion-resistant permanent magnet has a tin oxide film, which contains C of 100 to 1000ppm and has a film thickness of 0.1 to 1μm, on the surface of an Fe-B-Ra permanent magnet body containing the main phase consisting of a tetragonal crystalline phase. The tin oxide coating layer on this magnet body surface is one formed by a method, wherein after the surface of the magnet body dipped in a tin alkoxide compound solution (general formula, Sn (OR) n; R, alkyl group or alkyl group + other functional group; n, number of times of oxidation) or sprayed with the compound solution is dried, a heat treatment is performed and the layer is coated on the surface of the permanent magnet body, and this process is repeated two times or more to obtain a necessary film thickness. Thereby, the deterioration of the magnet characteristics of the permanent magnet from its initial magnet characteristics in the case where the magnet is left to stand for a long time under the severe condition of a corrosion-resisting test of a temperature of 80°C and 90% of a relative humidity is little and an Fe-B-Ra permanent magnet having stable high magnetic characteristics can be obtained at low cost.
Inventors:
Fumiaki Kikui
Masako Suzuki
Shigeyoshi Ikeda
Masako Suzuki
Shigeyoshi Ikeda
Application Number:
JP30931592A
Publication Date:
December 04, 2001
Filing Date:
October 22, 1992
Export Citation:
Assignee:
Sumitomo Special Metal Co., Ltd.
International Classes:
C22C38/00; H01F1/053; H01F1/057; H01F1/08; H01F7/02; H01F41/02; (IPC1-7): H01F1/08; C22C38/00; H01F1/053; H01F7/02; H01F41/02
Domestic Patent References:
| JP382742A |
Attorney, Agent or Firm:
Shigenobu Ikejou (1 person outside)