ALLOY RAW MATERIAL FOR RARE EARTH PERMANENT MAGNET, ALLOY POWDER FOR RARE EARTH PERMANENT MAGNET AND PRODUCTION OF RARE EARTH PERMANENT MAGNET

摘要

PROBLEM TO BE SOLVED: To provide a raw material for alloy powder for a permanent magnet raw material excellent in coercive force by a safe and simple method at a low cost, to provide alloy powder obtd. by pulverizing this raw material and to provide a method for producing the same. ;SOLUTION: An alloy having a compsn. expressed by R_xFe_100-x-u-vB_uCr_v, in which R denotes one or more kinds of elements selected from Y and lanthanoids, one or more kinds of Nd and Pr occupy≥50% therein, (x), (u) and (v) respectively satisfy 3at%≤x≤7at%, 15at%u≤25at% and 0.5at%≤v≤7 at%, and main structural phases are composed of metastable phase R₂Fe₂₃B₃ type compounds is subjected to heat treatment in a vacuum, in a nitrogen atmosphere or in an inert atmosphere to generate the disproportionation of the metastable phase R₂Fe₂₃B₃ type compounds.;COPYRIGHT: (C)1998,JPO