PRODUCTION OF RAW MATERIAL POWDER FOR PERMANENT MAGNET EXCELLENT IN MOLDABILITY

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing raw material powder for a permanent magnet excellent in moldability, especially in moldability at the time of manufacturing a bond magnet and productivity. SOLUTION: Acicular iron powder having aspect ratio of >=5:1 is heated at 800 to 900 deg.C while being flowed by air stream containing no oxygen and the heating is continued until the acicular iron powder is soln. heat treated to be columnar or dice-shaped or spherical iron powder having aspect ratio of <=3:1. The acicular iron powder containing or being stuck with magnetic characteristics improving components such as rare earth metal, rare earth metal oxide, boron, cobalt and nickel can be used.