MANUFACTURING METHOD FOR MAGNETIC POWDER, MANUFACTURING METHOD FOR ISOTROPIC BONDED MAGNET, MAGNETIC POWDER, AND ISOTROPIC BONDED MAGNET

摘要

PROBLEM TO BE SOLVED: To provide a magnet which has high magnetic flux density, superior magnetization properties, and reliability, especially in high heat resistance and in high anticorrosion properties.;SOLUTION: The bond magnet is manufactured by a method, having a process of obtaining a quenched thin belt by making a fused alloy collide against a peripheral face of a cooling roll, rotating at 1 to 60 [m/second] and by cooling and solidifying it, a process of obtaining a powder with an average particle diameter of 0.5 to 150μm, by grinding the quenched thin belt under a vacuum state, under a reduced pressure state, or in a non-oxidizing atmosphere, a process to obtain a magnetic powder by subjecting the powder to heat-treatment at 350 to 850°C and for 0.5 to 300 minutes, and a process to mold the magnetic powder, by mixing it with a bonding resin. In demagnetization curves in J-H curves showing magnetic properties at room temperature, when an irreversible magnetization ratio (χ_irr) is determined, when it passes away an origin in the figures J to H and that a point of intersection to a straight line with a tilt (J/H) of -3.8×10^-6 henry/m is a starting point, the irreversible magnetization ratio (χ_irr) is 5.0×10^-7 henry/m or smaller, and an intrinsic coercive force (Hcj) at room temperature is 406 to 717 kA/m.;COPYRIGHT: (C)2004,JPO&NCIPI