Method for producing oxide magnetic material based on permanent magnet

摘要

The present invention provides a method for manufacturing a permanent magnet based on oxide magnetic material, comprising a binder addition step for adding a binder to raw material powder containing oxide magnetic materials for mixing; a water content adjustment step for adjusting the water content of a molding mixture containing the raw material powder and the binder; an in-magnetic-field dry molding step for loading the molding mixture with adjusted water content into a mold and pressing it in a magnetic field applied while aligning the directions of easy magnetization of oxide magnetic material powder particles; and a sintering step for sintering the molded body; wherein the binder in the binder addition step is a wax based on fatty acid ester, and wherein the molding mixture charged into the mold in the in-magnetic-field dry molding step contains aggregates, in which the percentage of existence of aggregates in size of 500 mum or more is 0.01 to 0.80 wt %, thus obtaining the permanent magnet based on oxide magnetic material with excellent magnetic properties while cutting down on costs.