Patents by Inventor Masao Iwata

Masao Iwata 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: 4093477
    Abstract: The thermo-magnetic-treated anisotropic permanent magnet alloy of the present invention consists essentially of, by weight, 17 to 45% chromium, 3 to 14.5% cobalt, 0.2 to 5% silicon and balance substantially iron, preferably 23 to 35% chromium, 7 to 14.5% of cobalt, 0.3 to 3% silicon and balance substantially iron and has a residual magnetic flux density of 7000 Gauss or more and a coersive force of 300 Oersted or more. In order to obtain the alloy, an alloy having the above identified composition is initially aged at a temperature of 570.degree. C to 670.degree. C for a period of 10 minutes to 5 hours in a magnetic field and secondarily aged at a temperature within 200.degree. C below the thermo-magnetic treatment temperature for a period of 30 minutes to 50 hours.
    Type: Grant
    Filed: November 1, 1976
    Date of Patent: June 6, 1978
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masao Iwata, Hisao Yoshizawa
  • Patent number: 3989556
    Abstract: The semihard magnetic alloy of the present invention consists essentially of, by weight, 17 % to 45 % chromium, 3 % to 14 % cobalt, 0.2 % to 10 % titanium and balance substantially iron and has a residual magnetic flux density of 7,000 Gauss or more and a coercive force of 100 to 600 Oersted. Said alloy is produced by solution treating an alloy having the above-indicated composition at a temperature of 650.degree. C to 1,200.degree. C, and then either keeping the solution-treated alloy at a temperature of not higher than 650.degree. C for a given period of time and repeatedly aging said alloy in multi-stage at gradually lowered temperatures, or cooling the solution-treated alloy continuously from a temperature of not higher than 700.degree. C down to at least 550.degree. C at a rate of not higher than 50.degree. C per hour.
    Type: Grant
    Filed: March 21, 1975
    Date of Patent: November 2, 1976
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masao Iwata, Yoichi Ishijima
  • Patent number: 3982972
    Abstract: The semihard magnetic alloy of the present invention consists essentially of, by weight, 17 to 45 % chromium, 3 to 14 % cobalt, 0.2 to 5 % silicon and balance substantially iron, preferably 23 to 35 % chromium, 6 to 12 % cobalt, 0.3 to 3 % silicon and balance substantially iron and has a residual magnetic flux density of 7,000 Gauss or more and a coersive force of 100 to 600 Oersted. Said alloy is produced by solution treating an alloy having the above indicated composition at a temperature of 650.degree.C. to 1,300.degree.C., preferably 850.degree.C. to 1,085.degree.C., and then either maintaining the solution-treated alloy at a temperature of not higher than 650.degree.C. for a given period of time and repeatedly aging said alloy in multi-stage at gradually lowered temperatures, or cooling the solution-treated alloy continuously from a temperature of not higher than 700.degree.C. down to at least 550.degree.C. at a rate of not higher than 50.degree.C. per hour.
    Type: Grant
    Filed: March 21, 1975
    Date of Patent: September 28, 1976
    Assignee: Hitachi Metals, Ltd.
    Inventors: Masao Iwata, Yoichi Ishijima, Osamu Fujita