Patent ID: 7967919
Filing Date: 2011-06-28
Classification: B22F,C22C,H01F,H02K

Abstract:
1. A method for manufacturing a rare earth-iron bonded magnet comprising: a first step of covering a rare earth-iron magnet powder with oligomer or prepolymer to provide a surface-treated magnet powder, wherein the oligomer or prepolymer has a functional group for fixing the rare earth-iron magnet powder; a second step of melting a stretchable polymer and kneading the melted stretchable polymer with the surface-treated magnet powder at a temperature equal to or higher than a melting point of the polymer to coarsely crush a resultant material to provide a granule; a third step of dry blending an additive and a hardener with the granule to provide a compound; a fourth step of compressing the compound under conditions in which the oligomer or prepolymer, the polymer, and the hardener are heated to melt and to flow at a temperature equal to or higher than the melting points of the oligomer or prepolymer, the polymer, and the hardener to provide a green compact; and a fifth step of stretching the rare earth-iron bonded magnet to transform the shape to any of a circular-shape or a circular arc-like shape.