FePt magnet and manufacturing method thereof
AssigneeAichi Steel Corporation
InventorsHitoshi Aoyama, Yoshinobu Honkura, Takumi Asano
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Abstract
The present invention offers a minute-sized magnet with superior magnetic energy product (BH)max and coercivity iHc, as well as superior anti-corrosive properties. This magnet is comprised of an alloy comprised of 35-55 atomic % platinum, 0.0 01-10 atomic % third element, which is one or more elements from groups IVa, Va, IIIb, or IVb, and a remainder of iron and other unavoidable impurities. The average crystal size of this FePt alloy is 0.3 μm. By mixing an FePt alloy with a specific element in a designated ratio, an FePt magnet with more excellent characteristics than ones made from previous alloys was successfully made.
Claims7
The FePt magnets made of an alloy comprising 35-55% platinum, 0.001-10% of one or more kinds of the third elements selected from the group consisting of IVa , Va, IIIb and IVb metallic elements and, for a remainder of iron and some unavoidable impurities, an average crystal particle size of said alloy being not more than 0.3 μm.
A manufacturing method of the FePt magnets made of an alloy comprising 35-55% platinum, 0.001-10% of one or more kinds of the third elements selected from the group consisting of IVa, Va, IIIb and IVb elements, and a remainder of iron and some unavoidable impurities, said method including a film-forming process in which said alloy is made into a film state through a sputtering or a vacuum deposition method, and a heat-treatment process in which said alloy is heat treated as to have a CuAu (L10) type face-centered tetragonal structure.
Dependencies are inferred from the claim text.