PARIDLY COOLED ALLOY FOR IRON BASED RARE EARTH ALLOY MAGNET AND METHOD FOR PRODUCING IRON BASED RARE EARTH ALLOY MAGNET

摘要

PROBLEM TO BE SOLVED: To provide a permanent magnet which exhibits high coercive force and magnetization in spite of the low content of rare earth elements, and further has excellent squareness of a demagnetization curve. SOLUTION: The molten meal of an alloy whose compositional formula is expressed by (Fe1-mTm)100-x-y-zQxRyMz (T is one or more elements selected from the group consisting of Co and Ni; Q is one or more elements selected from the group consisting of B and C; R is one or more rare earth metal elements including Y; and M is at least one element selected from the group consisting of Ti, Zr and Hf), and in which the compositional ratios of (x), (y), (z) and (m) respectively satisfy 10=30 kPa to produce a rapidly cooled alloy containing an R2Fe14B type compound phase having the average particle size of <=50 nm. Ferromagnetic iron based borides are present in a fine state on the grain boundary of the R2Fe14B type compound phase in a nanocomposite magnet produced from the rapidly cooled alloy.