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US 2003/0213534 A1Published application
Magnetic powder and isotropic bonded magnet
AssigneeSeiko Epson Corporation
InventorsAkira Arai, Hiroshi Kato
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AssigneeSeiko Epson Corporation
InventorsAkira Arai, Hiroshi Kato
Estimating the term…
Disclosed herein is a magnetic powder which can provide a magnet having a high magnetic flux density and excellent magnetizability and reliability especially excellent heat resisting property (heat stability). The magnetic powder is composed of an alloy composition represented by Rx(Fe1-yCOy)100-x-z-wBzAlw (where R is at least one kind of rare-earth element, x is 8.1 - 9.4 at %, y is 0 - 0.30, z is 4.6 - 6.8 at %, and w is 0.02 - 1.5 at %), the magnetic powder being constituted from a composite structure having a soft magnetic phase and a hard magnetic phase, wherein the magnetic powder has characteristics in which, when the magnetic powder is formed into an isotropic bonded magnet by mixing with a binding resin and then molding it, the irreversible susceptibility (χirr) which is measured by using an intersectioning point of a demagnetization curve in the J-H diagram representing the magnetic characteristics at the room temperature and a straight line which passes the origin in the J-H diagram and has a gradient (J/H) of −3.8 ×10−6H/m as a starting point is less than 5.0×10−7H/m, and the intrinsic coercive force (HCJ) of the magnet at the room temperature is in the range of 406-717 kA/m.
Magnetic powder composed of an alloy composition represented by Rx(Fel-yCoy)100-x-z-wBzAlw, (where R is at least one kind of rare-earth element, x is 8.1 -9.4 at %, y is 0 -0.30, z is 4.6-6.8at %, and w is 0.02-1.5 at %), the magnetic powder being constituted from a composite structure having a soft magnetic phase and a hard magnetic phase, wherein the magnetic powder has characteristics in which, when the magnetic powder is formed into an isotropic bonded magnet by mixing with a binding resin and then molding it, the irreversible susceptibility (χirr) which is measured by using an intersectioning point of a demagnetization curve in the J-H diagram representing the magnetic characteristics at the room temperature and a straight line which passes the origin in the J-H diagram and has a gradient (J/H) of −3.8 ×10 −6H/m as a starting point is less than 5.0×10−7 H/m, and the intrinsic coercive force (HCJ) of the magnet at the room temperature is in the range of 406-717 kA/m.
An isotropic rare-earth bonded magnet formed by binding a magnetic powder containing Al with a binding resin, wherein the isotropic rare-earth bonded magnet is characterized in that the irreversible susceptibility (χirr) which is measured by using an intersectioning point of a demagnetization curve in the J-H diagram representing the magnetic characteristics at the room temperature and a straight line which passes the origin in the J-H diagram and has a gradient (J/H) of −3.8×10−6H/m as a starting point is less than 5.0×10−7 H/m, and the intrinsic coercive force (HCJ) of the magnet at the room temperature is in the range of 406-717 kA/m.
Dependencies are inferred from the claim text.