Rare earth-iron system permanent magnet

Abstract

Abstract PURPOSE:To simplify a manufacturing process, and to improve performance and reduce cost by a method wherein an alloy having a specific composition is dissolved and casted, crystal grains are fined through hot working at a specific temperature, the crystallographic axes of the crystal grains are oriented in the specified direction and the casted alloy is brought to an anisotropic state magnetically. CONSTITUTION:An alloy having a composition shown in formula RFeBCu and consisting of 8-30% R (a rare earth element containing Y) at an atomic percentage, 2-28% B, not more than 6% Cu, and iron and unavoidable impurities on manufacture as the remainder is dissolved and casted, an ingot is hot-worked at a temperature of 500 deg.C or more, crystal grains are fined, the crystallographic axes of the crystal grains are oriented in the specified direction, and the cast alloy is brought to an anisotropic state magnetically. Coercive force can be increased through heat treatment at 250 deg.C or over before hot working, after hot working or before and after hot working. Not more than 50 atomic % Fe is replaced with Co in order to improve temperature characteristics. One kind or two kinds or more of Al, Ga, Si, Ti, Zr, Hf, V, Nb, Cr, Mo, W, Mn, and Bi are added at 6 % or less in order to enhance magnetic characteristics.

Inventors

• 👤 Koji Akioka
• 👤 Osamu Kobayashi
• 👤 Toshiaki Yamagami
• 👤 Tatsuya Shimoda

Bibliographic Details