Global Patent Index - EP 0338597 A2

EP 0338597 A2 19891025 - Permanent magnets.

Title (en)

Permanent magnets.

Title (de)

Dauermagnete.

Title (fr)

Aimants permanents.

Publication

EP 0338597 A2 19891025 (EN)

Application

EP 89111005 A 19850227

Priority

  • EP 85102200 A 19850227
  • JP 3692384 A 19840228
  • JP 3692484 A 19840228
  • JP 3692584 A 19840228
  • JP 3692684 A 19840228

Abstract (en)

Permanent magnet materials, produced according to the following steps: forming an alloy powder having a mean particle size of 0.3-80 mu m and composed of, in atomic percentage, 8-30 % R (provided that R is at least one of rare earth elements including Y), 2-28 % B, and the balance Fe and inevitable impurities, sintering the formed body at a temperature of 900-1200 DEG C, subjecting the sintered body to a primary heat treatment at a temperature of 750-1000 DEG C, then cooling the resultant body to a temperature of no higher than 680 DEG C at a cooling rate of 3-2000 DEG C/min, and further subjecting the thus cooled body to a secondary heat treatment at a temperature of 480-700 DEG C. Magnets having an energy product (BH)max of at least 20 MGOe and a coercitive force (iHc) of at least 10 kOe or magnets having an energy product (BH)max of 40 MGOe or more can be obtained by specific compositions.

IPC 1-7

B22F 3/24; C22C 1/04; H01F 1/053; H01F 1/08

IPC 8 full level

B22F 3/24 (2006.01); C22C 1/04 (2006.01); H01F 1/057 (2006.01)

CPC (source: EP)

B22F 3/24 (2013.01); C22C 1/0441 (2013.01); H01F 1/0577 (2013.01)

Designated contracting state (EPC)

BE CH DE FR GB IT LI NL SE

DOCDB simple family (publication)

EP 0338597 A2 19891025; EP 0338597 A3 19911113; EP 0338597 B1 19950111

DOCDB simple family (application)

EP 89111005 A 19850227