Title:
RESIN-MOLDED MAGNET
Document Type and Number:
Japanese Patent JP3232037
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To improve the mechanical strength by carrying out metal Ni plating on a R-Fe-B bonded annular, thin plate, and discoidal magnets, using a specified plating bath.
SOLUTION: R-Fe-B magnetic material powder of required composition and property is injection-molded or rolled and compression-molded to provide a resin-molded annular, thin plate, and discoidal magnets having a thickness of 0.5 to 10 mm. After this magnet is cleaned with water, the magnet is impregnated with a solution of a compound such as acidic ammonium fluoride to which a surface active agent is added, thus carrying out surface activation. Then, using a plating bath which is obtained by properly selecting nickel sulfate, sodium sulfate, magnesium sulfate, ammonium citrate, or sodium citrate, cobalt sulfate, and boric acid in accordance with the composition of a bonded magnet 3, Ni electroplating is carried out by using a nickel chip 1 for an anode plate. After cleaning with water, sealing is carried out and cleaning is properly carried out. Thus, a Ni plating layer having extremely high coating strength can be easily formed, and a bonded magnet having high corrosion resistance and high strength can be provided.
Inventors:
Michio Yamashita
Akira Kitagawa
Hiroshi Watanabe
Ki Nishizawa
Akira Kitagawa
Hiroshi Watanabe
Ki Nishizawa
Application Number:
JP2284598A
Publication Date:
November 26, 2001
Filing Date:
January 19, 1998
Export Citation:
Assignee:
Sumitomo Special Metal Co., Ltd.
International Classes:
C25D7/00; H01F1/053; H01F1/08; (IPC1-7): H01F1/08; C25D7/00; H01F1/053
Attorney, Agent or Firm:
Shigenobu Ikejou (1 person outside)
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