A composite rare-earth anisotropic bonded magnet, composite rare-earth anisotropic bonded magnet compound, and methods for their production

摘要

The bonded magnet of the present invention, in which average particle diameter and compounding ratio are specified, is comprised of Cobalt-less R1 d-HDDR coarse magnet powder that has been surface coated with surfactant, R2 fine magnet powder that has been surface coated with surfactant (R1 and R2 are rare-earth metals), and a resin which is a binder. The resin, a ferromagnetic buffer in which R2 fine magnet powder is uniformly dispersed, envelops the outside of the Cobalt-less R1 d-HDDR coarse magnet powder. Despite using Cobalt-less R1 d-HDDR anisotropic magnet powder, which is susceptible to fracturing and therefore vulnerable to oxidation, the bonded magnet of the present invention exhibits high magnetic properties along with extraordinary heat resistance.