Anisotropic bonded magnets fabricated via surfactant-assisted ball milling and magnetic-field processing

Anisotropic bonded magnets are fabricated by surfactant-assisted ball milling in a magnetic field and magnetic field alignment of the milled chip-like nanoparticles of the Sm-Co and Nd-Fe-B materials. It is found that the application of magnetic fields during the ball milling strengthens the anisotropy of the chips and therefore improves the alignment. For SmCo(5) phase-based chips, for instance, energy products up to 26.0 MGOe and 19.1 MGOe are obtained for the chips and the bonded magnets, respectively. This combined technique opens a new approach to the fabrication of anisotropic bonded magnets for various applications.