Manufacture of alloy powder for rare earth-boron-iron group magnetic anisotropic permanent magnet

Abstract

Abstract PURPOSE:To obtain a permanent magnet having stable quality and excellent magnetic characteristics by chainging a molten alloy, components and contents thereof are specified, into powder, a main phase thereof consists of a tetragonal compound and grain size and crystalline grain size thereof are specified, through a spray method in a non- oxidizing atmosphere. CONSTITUTION:A molten alloy mainly comprising 8-30atom% R, 2-28atom% B and 42-90atom% Fe is changed into powder, which has composite texture of 50mum-1mm. mean grain size and not less than 5mum crystalline grain size and a main phase thereof is composed of a tetragonal compound, through a spray method in a non-oxidizing atmosphere. Frequency is applied by a coil such as a high-frequency coil 3 arranged on the outer circumference of a crucible 1 and the alloy is high-frequency melted, a stopper 4 fitted to the inlet of a molten metal nozzle 2 is elevated, a molten metal is ejected from the nose of the molten metal nozzle 2, and argon gas at the velocity of flow less than the speed of sound is ejected from an inert gas nozzle 5 at a spray angle alpha of 45 deg. and the alloy is powdered. collected powder is pulverized at the next stage, and molded in a magnetic field and sintered, thus manufacturing a magnetic anisotropic permanent magnet.

Inventors

• 👤 Michio Yamashita
• 👤 三千雄 山下
• 👤 Motoharu Suehiro
• 👤 末広　元春

Bibliographic Details