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US 6,855,265 B2Granted
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 bonded magnet having excellent magnetic properties and having excellent reliability especially excellent 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 7.1-9.9 at %, y is 0-0.30, z is 4.6-6.9 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 magnetic properties in which, when the magnetic powder is formed into an isotropic bonded magnet having a density ρ[Mg/m3] by mixing with a binding resin and then molding it, the maximum magnetic energy product (BH)max[kJ/m3] of the bonded magnet at the room temperature satisfies the relationship represented by the formula (BH)max/ρ2[×10−9 J·m3/g2]≧2.1, and the intrinsic coercive force (HCJ) of the bonded magnet at the room temperature is in the range of 320-720 kA/m.
An isotropic bonded magnet formed by binding a magnetic powder containing Al with a binding resin, wherein the isotropic bonded magnet is characterized in that, the magnetic powder is composed of an alloy composition represented by Rx(Fe1-yCoy)100-x-z-wBzAlw (where R is at least one rare-earth element, x is 7.1-9.9 at %, y is 0-0.30, z is 4.6-6.9 at %, and W is 0.02-1.5 at %) when the density of the isotropic bonded magnet is ρ[Mg/m3], the maximum magnetic energy product (BH)max[kJ/m3] at room temperature satisfies the relationship represented by the formula (BH)maxρ2[×10−9 J·m3/g2]≧2.1, and the intrinsic coercive force (HCJ) of the bonded magnet at the room temperature is in the range of 320-720 kA/m.
An isotropic bonded magnet formed by binding a magnetic powder containing Al with a binding resin, wherein the isotropic bonded magnet is characterized in that, the magnetic powder is composed of an alloy composition represented by Rx(Fe1-yCoy)100-x-z-wBzAlw (where R is at least one rare-earth element, x is 7.1-9.9 at %, y is 0-0.30, z is 4.6-6.9 at %, and W is 0.02-1.5 at %) when the density of the isotropic bonded magnet is ρ[Mg/m3], the remanent magnetic flux density Br[T] at room temperature satisfies the relationship represented by the formula of Br/ρ[×10−6 T·m3/g]≧0.125.
Dependencies are inferred from the claim text.