Title :
Structural and magnetic properties of sintered Nd14.4Fe 67.0-xCo11.8MoxB6.8 magnets
Author :
Rodewald, W. ; Schrey, P.
Author_Institution :
Vacuumschmelze GmbH, West Germany
fDate :
9/1/1989 12:00:00 AM
Abstract :
Additions of Mo up to 1.4 at.% to Nd-Fe-Co-B alloys are shown to result in the precipitation of the tetragonal Mo2FeB2 compound in Nd2Fe14B grains. During annealing of sintered magnets the precipitates grow because the solubility of Mo decreases at lower temperatures. The precipitates dilute the magnetic moments of sintered Nd-Fe-Co-Mo-B magnets so that the saturation polarization decreases with increasing Mo concentration. The dimensions of the precipitates are too large and their density is too low to pin the magnetic domain walls. The magnetization curve of thermally demagnetized magnets shows that the coercivity is determined by nucleation of reversed domains
Keywords :
annealing; boron alloys; cobalt alloys; coercive force; ferromagnetic properties of substances; iron alloys; magnetisation; molybdenum alloys; neodymium alloys; permanent magnets; precipitation; sintering; Mo2FeB2 compound; Nd14.4Fe67.0-xCo11.8Mox B6.8; Nd2Fe14B grains; annealing; coercivity; magnetic domain walls; magnetic moments; magnetic properties; magnetization curve; precipitation; reversed domain nucleation; saturation polarization; sintered magnets; solubility; Annealing; Iron alloys; Magnetic domain walls; Magnetic moments; Magnetic properties; Magnetization; Magnets; Neodymium; Polarization; Temperature;
Journal_Title :
Magnetics, IEEE Transactions on
