Sintered permanent magnet material and its production

Abstract

Abstract PURPOSE:To obtain a permanent magnet having superior magnetic properties by incorporating Cu to a rare-earth sintered permanent magnet containing Fe-B-rare earths as a basic series and also containing Co and subjecting the above magnet to sintering and then to heat treatment under specific conditions. CONSTITUTION:Powdered raw materials are mixed so that they are formed into a composition consisting of, by atom., 12-17%, in total, of Nd and Pr, 5-14% B, <20% Co, 0.02-0.5% Cu, and the balance Fe, which is pulverized in an inert-gas atmosphere of Ar, etc. The above powdered raw materials are compacted in a magnetic field and the resulting green compact is sintered in a reducing or nonoxidizing atmosphere at 900-1,200 deg.C, and the sintered compact is subjected to heat treatment in vacuum, in an inert-gas atmosphere, or in a reducing atmosphere at 430-600 deg.C for about 5min-40hr. By this method, the sintered permanent magnet having high coercive force, and superior square characteristic in demagnetization curve can be obtained.

Inventors

• 👤 Hiroshi Nagata
• 👤 浩 永田
• 👤 Satoru Hirozawa
• 👤 哲 広沢

Bibliographic Details