Patents by Inventor Yoshiki Kuwabara

Yoshiki Kuwabara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6368551
    Abstract: The method for preparation of sintered permanent magnets according to the present invention comprises the steps of: mixing fully fine powder of a crystalline mother alloy for permanent magnet containing a rare-earth element, Fe and B as the essential components with fine powder of zinc oxide, compaction molding the resulted mixture in the presence of a magnetic field, sintering the compacted mixture in vacuum to cause generation of oxygen and metallic zinc by thermal decomposition of the zinc oxide; segregation of a part of metallic component in the mother alloy at the boundary and inside of the mother alloy crystal; formation of amorphous metallic oxide by forced oxidation of the segregated metal with the generated oxygen; crystallization of the amorphous metallic oxide; formation of an epitaxial junction between the crystallized metallic oxide and the mother alloy crystal; and evaporation of the metallic zinc into the vacuum, and quenching the sintered compact.
    Type: Grant
    Filed: August 16, 2000
    Date of Patent: April 9, 2002
    Assignee: Sanei Kasei Co., Ltd.
    Inventors: Shigenobu Sekine, Yuko Kawasaki, Yoshiki Kuwabara, Hiroji Sato, Minoru Narita, Kazushi Suzuki, Koichi Tono, Keiji Okada, Kenji Sakaguchi, Mitsuhisa Hirata