The Foundation: the Research Institute of Electric and Magnetic Alloys

Kiyoshi Watanabe

Hakaru Masumoto, Deceased

Hakaru Masumoto

By Hiroshi Matushima, Executor

Hiroshi Matushima, Executor

The disclosed permanent magnet has a coercive force of larger than 500 Oe, a residual magnetic flux density of larger than 5 kG, and a maximum energy product of larger than 2 MGOe, and it consisting essentially of 48.about.66.9 Atm % of iron, 33.about.47 Atm % of platinum, and 0.1.about.10 Atm % of niobium. It includes a crystal structure of an incomplete single .gamma.1 phase of a face-centered tetragonal system due to either the composition thereof or heat treatment applied thereto. The permanent magnet are made by heating an alloy of the above main composition at 900.degree..about.1,400.degree. for one minute to ten hours and quenching the alloy at a high speed of faster than 30.degree. C./minute but slower than 2,000.degree. C./sec.

Fc-Pt-Nb permanent magnet with an ultra-high coercive force and a large

The disclosed permanent magnet has a coercive force of larger than 500 Oe, a residual magnetic flux density of larger than 5 kG, and a maximum energy product of larger than 2 MGOe, and it consisting essentially of 48.about.66.9 Atm % of iron, 33.about.47 Atm % of platinum, and 0.1.about.10 Atm % of niobium. It includes a crystal structure of an incomplete single .gamma..sub.1 phase of a face-centered tetragonal system due to either the composition thereof or heat treatment applied thereto. The permanent magnet is made by heating an alloy of the above main composition at 900.degree..about.400.degree. for one minute to ten hours and quenching the alloy at a high speed of faster than 30.degree. C./minute but slower than 2,000.degree. C./sec.

Fe-Pt-Nb permanent magnet with an ultra-high coercive force and a large

The disclosed permanent magnet consists of an iron-palladium alloy consisting of 25 to 40 atomic % of palladium, and the remainder of iron with less than 0.5 atomic % of impurities or an iron-palladium-silver alloy consisting of 19.5 atomic % of palladium, 0.1 to 27.5 atomic % of silver and the remainder of iron with less than 0.5 atomic % of impurities and having a crystalline structure with fine dispersion of .alpha.+.gamma..sub.1 phase in a matrix, so that the permanent magnet has a coercive force of higher than 500 Oe, a residual magnetic flux density of larger than 6 kG, and a maximum energy product of larger than 2 MG.Oe. The disclosed method of producing the aforementioned permanent magnet comprises steps of homogenizing solid solution treatment at a temperature depending on the specific alloy composition, cooling, and tempering at a suitable temperature so as to generate the aforementioned crystalline structure.

High-coercive-force permanent magnet with a large maximum energy product

The disclosed permanent magnet has a coercive force of 500 Oe or more, a idual magnetic flux density of 5 kG or more, and a maximum energy product of 2 MG. Oe or more. The magnet alloy consists essentially of platinum and iron, and has an initial state of homogeneous dispersion of .gamma..sub.1 phase of face-centered tetragonal type in a .gamma. phase matrix of face-centered cubic type. To produce the magnet, the alloy is heated at 900.degree. to 1,400.degree. C. for 1 minute to 100 hours for homogenizing solid solution treatment, and quenched in water or in air at a rate of 30.degree. C./minute to 2,000.degree. C./second.

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Sendai, Japan

Kiyoshi Watanabe