High energy product permanent magnet having improved intrinsic coercivity and method of making same
- Berkeley, CA
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.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Number(s):
- US 4968347
- OSTI ID:
- 867585
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
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
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