Improvement of coercive force in Fe-Ce·Didymium-B powder prepared by conventional powder techniques

Enhancements of the coercive force (iHc) of Fe- (33-38)wt%(5Ce´Didymium)-1wt%B powders were tried by chemical polishing and the several annealing methods. The chemical polishing lowers the coercive force of powders by creating the etch pits on the surfaces of the ground powders. The optimum process to prepare the powders with good magnetic properties was: the green compacts with magnetic alignment were annealed at 1050°C, ground into powders, and underwent 2nd- annealing. The anisotropic powders resulted in the coercive force of 7-8 kOe. Utilizing the presently prepared powders, the anisotropic resin-bonded magnets are formed with (BH)max of nearly 8 MGOe. This will be then the first report to demonstrate that the anisotropic bonded magnets can be produced by the conventional powder techniques.