DOE Patents title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: High energy product permanent magnet having improved intrinsic coercivity and method of making same

Abstract

A high energy rare earth-ferromagnetic metal permanent magnet is disclosed which is characterized by improved intrinsic coercivity and is made by forming a particulate mixture of a permanent magnet alloy comprising one or more rare earth elements and one or more ferromagnetic metals and forming a second particulate mixture of a sintering alloy consisting essentially of 92-98 wt. % of one or more rare earth elements selected from the class consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures of two or more of such rare earth elements, and 2-8 wt. % of one or more alloying metals selected from the class consisting of Al, Nb, Zr, V, Ta, Mo, and mixtures of two or more of such metals. The permanent magnet alloy particles and sintering aid alloy are mixed together and magnetically oriented by immersing the mixture in an axially aligned magnetic field while cold pressing the mixture. The compressed mixture is then sintered at a temperature above the melting point of the sintering aid and below the melting point of the permanent magnet alloy to thereby coat the particle surfaces of the permanent magnetic alloy particles with the sintering aid while inhibiting migration of themore » rare earth element in the sintering aid into the permanent magnet alloy particles to thereby raise the intrinsic coercivity of the permanent magnet alloy without substantially lowering the high energy of the permanent magnet alloy.« less

Inventors:
 [1];  [1]
  1. Berkeley, CA
Issue Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
OSTI Identifier:
867585
Patent Number(s):
4968347
Assignee:
United States of America as represented by United States (Washington, DC)
Patent Classifications (CPCs):
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01F - MAGNETS
B - PERFORMING OPERATIONS B22 - CASTING B22F - WORKING METALLIC POWDER
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
energy; product; permanent; magnet; improved; intrinsic; coercivity; method; rare; earth-ferromagnetic; metal; disclosed; characterized; forming; particulate; mixture; alloy; comprising; earth; elements; ferromagnetic; metals; sintering; consisting; essentially; 92-98; wt; selected; gd; tb; tm; mixtures; 2-8; alloying; nb; zr; particles; mixed; magnetically; oriented; immersing; axially; aligned; magnetic; field; cold; pressing; compressed; sintered; temperature; melting; below; coat; particle; surfaces; inhibiting; migration; element; raise; substantially; lowering; cold pressing; metals selected; magnetic alloy; elements selected; earth elements; axially aligned; alloy comprising; permanent magnet; consisting essentially; magnetic field; rare earth; alloy particles; permanent magnetic; particulate mixture; earth element; alloying metal; alloy consisting; metal permanent; particle surface; energy product; intrinsic coercivity; improved intrinsic; alloy particle; axially align; /75/148/419/

Citation Formats

Ramesh, Ramamoorthy, and Thomas, Gareth. High energy product permanent magnet having improved intrinsic coercivity and method of making same. United States: N. p., 1990. Web.
Ramesh, Ramamoorthy, & Thomas, Gareth. High energy product permanent magnet having improved intrinsic coercivity and method of making same. United States.
Ramesh, Ramamoorthy, and Thomas, Gareth. Mon . "High energy product permanent magnet having improved intrinsic coercivity and method of making same". United States. https://www.osti.gov/servlets/purl/867585.
@article{osti_867585,
title = {High energy product permanent magnet having improved intrinsic coercivity and method of making same},
author = {Ramesh, Ramamoorthy and Thomas, Gareth},
abstractNote = {A high energy rare earth-ferromagnetic metal permanent magnet is disclosed which is characterized by improved intrinsic coercivity and is made by forming a particulate mixture of a permanent magnet alloy comprising one or more rare earth elements and one or more ferromagnetic metals and forming a second particulate mixture of a sintering alloy consisting essentially of 92-98 wt. % of one or more rare earth elements selected from the class consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures of two or more of such rare earth elements, and 2-8 wt. % of one or more alloying metals selected from the class consisting of Al, Nb, Zr, V, Ta, Mo, and mixtures of two or more of such metals. The permanent magnet alloy particles and sintering aid alloy are mixed together and magnetically oriented by immersing the mixture in an axially aligned magnetic field while cold pressing the mixture. The compressed mixture is then sintered at a temperature above the melting point of the sintering aid and below the melting point of the permanent magnet alloy to thereby coat the particle surfaces of the permanent magnetic alloy particles with the sintering aid while inhibiting migration of the rare earth element in the sintering aid into the permanent magnet alloy particles to thereby raise the intrinsic coercivity of the permanent magnet alloy without substantially lowering the high energy of the permanent magnet alloy.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1990},
month = {1}
}