EP 0286357 A2 19881012 - Multiphase permanent magnet of the Fe-B-MM type.
Title (en)
Multiphase permanent magnet of the Fe-B-MM type.
Title (de)
Fe-B-MM-Typ-Dauermagnet mit verschiedenen Phasen.
Title (fr)
Aimant permanent du type Fe-B-MM à phases multiples.
Publication
Application
Priority
US 3486287 A 19870406
Abstract (en)
A method is disclosed for producing a permanent magnet of the Fe-B-MM type, comprising: (a) preparing a metallic powder having a mean particle size of 2-5 microns and having a composition comprising, by atomic weight percent: 60-80% Fe, 1-8% Al, 6-10% B, .1-.43% oxygen, 0-5% Dy and/or 0-10% Ni, and 12-22% MM, where MM is a misch metal (preferably having at least four naturally occurring insoluble cerium earth metals with a least 20% of the misch metal consisting of cerium and lanthanum), the powder having essentially a multiphase crystalline structure dominated by at least two R2Fe14B phases; (b) aligning such powder in a magnetic field; (c) compacting the aligned powder into shapes; (d) sintering such shapes at a temperature and for a period of time (i.e., in the range of 1000-1100 DEG C for .5-9 hours) to fuse the powder and increase the proportion of said R2Fe14B phases to at least 70% by volume of the shapes; and preferably (e) anealing the sintered shapes at a temperature (i.e., in the range of 550-650 DEG C for 1-4 hours) to cause the shapes to consist essentially of at least two R2Fe14B phases comprising the matrix and the phase RFe4B4 and the R-rich phase residing essentially in the grain boundaries.
IPC 1-7
IPC 8 full level
B22F 3/10 (2006.01); B22F 3/12 (2006.01); H01F 1/057 (2006.01); H01F 1/08 (2006.01)
CPC (source: EP KR)
B22F 3/101 (2013.01 - EP); B22F 3/12 (2013.01 - EP); H01F 1/00 (2013.01 - KR); H01F 1/0577 (2013.01 - EP)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0286357 A2 19881012; EP 0286357 A3 19900606; AU 1415488 A 19881006; AU 608309 B2 19910328; BR 8801585 A 19881108; JP S63262805 A 19881031; KR 880013194 A 19881130
DOCDB simple family (application)
EP 88303018 A 19880405; AU 1415488 A 19880405; BR 8801585 A 19880405; JP 8396888 A 19880405; KR 880003727 A 19880401