Patents by Inventor Mahoro Fujihara

Mahoro Fujihara 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).

  • Method for producing surface-modified rare earth metal-based sintered magnet
    Patent number: 9558885
    Abstract: An object of the present invention is to provide a method for producing a surface-modified rare earth metal-based sintered magnet having extremely excellent corrosion resistance even in an environment with fluctuating temperature and humidity and also having excellent magnetic characteristics. The method for producing a surface-modified rare earth metal-based sintered magnet of the present invention as a means for achieving the object is characterized by comprising a step of subjecting a rare earth metal-based sintered magnet to a heat treatment at 200° C. to 600° C. in an atmosphere having an oxygen partial pressure of 1×103 Pa to 1×105 Pa and a water vapor partial pressure of 45 Pa or less with the ratio between the oxygen partial pressure and the water vapor partial pressure (oxygen partial pressure/water vapor partial pressure) being 450 to 20000.
    Type: Grant
    Filed: June 29, 2011
    Date of Patent: January 31, 2017
    Assignee: HITACHI METALS, LTD.
    Inventors: Mahoro Fujihara, Koshi Yoshimura
  • Method for producing surface-modified rare earth metal-based sintered magnet and surface-modified rare earth metal-based sintered magnet
    Patent number: 9175376
    Abstract: An objective of the present invention is to provide a rare earth metal-based sintered magnet having imparted thereto sufficient corrosion resistance by an oxidative heat treatment, which is resistant even in an environment of fluctuating humidity, while suppressing the deterioration of the magnetic characteristics ascribed to the oxidative heat treatment, and to provide a method for producing the same.
    Type: Grant
    Filed: September 26, 2008
    Date of Patent: November 3, 2015
    Assignee: HITACHI METALS, LTD.
    Inventors: Mahoro Fujihara, Koshi Yoshimura, Atsushi Kikugawa
  • METHOD FOR PRODUCING SURFACE-MODIFIED RARE EARTH METAL-BASED SINTERED MAGNET
    Publication number: 20130098509
    Abstract: An object of the present invention is to provide a method for producing a surface-modified rare earth metal-based sintered magnet having extremely excellent corrosion resistance even in an environment with fluctuating temperature and humidity and also having excellent magnetic characteristics. The method for producing a surface-modified rare earth metal-based sintered magnet of the present invention as a means for achieving the object is characterized by comprising a step of subjecting a rare earth metal-based sintered magnet to a heat treatment at 200° C. to 600° C. in an atmosphere having an oxygen partial pressure of 1×103 Pa to 1×105 Pa and a water vapor partial pressure of 45 Pa or less with the ratio between the oxygen partial pressure and the water vapor partial pressure (oxygen partial pressure/water vapor partial pressure) being 450 to 20000.
    Type: Application
    Filed: June 29, 2011
    Publication date: April 25, 2013
    Applicant: HITACHI METALS, LTD.
    Inventors: Mahoro Fujihara, Koshi Yoshimura
  • METHOD FOR PRODUCING SURFACE-MODIFIED RARE EARTH METAL-BASED SINTERED MAGNET AND SURFACE-MODIFIED RARE EARTH METAL-BASED SINTERED MAGNET
    Publication number: 20100252145
    Abstract: An objective of the present invention is to provide a rare earth metal-based sintered magnet having imparted thereto sufficient corrosion resistance by an oxidative heat treatment, which is resistant even in an environment of fluctuating humidity, while suppressing the deterioration of the magnetic characteristics ascribed to the oxidative heat treatment, and to provide a method for producing the same.
    Type: Application
    Filed: September 26, 2008
    Publication date: October 7, 2010
    Applicant: HITACHI METALS, LTD.
    Inventors: Mahoro Fujihara, Koshi Yoshimura, Atsushi Kikugawa