| 摘要 |
PURPOSE:To contrive improvement in magnetic characteristics, especially in coersive force and squareness, of the titled magnet material by a method wherei Fe-B-R-M alloy powder of a fixed range containing an additive element M (V, Nb, Ta, Mo, W, Cr and Al) is formed using FeBR as the base, is sintered and then a heat treatment is performed. CONSTITUTION:The alloy powder has the composition (FeBR composition) consisting of 8-30 atomic percentage of R (provided that at least R consists of one kind of rate-earth element containing Y), 2-28% of B, one or more kinds of additive element M of the prescribed percentage or below (provided that, excluding M:0%, M is V:9.5% or below, Nb:12.5% or below, Ta:10.5% or below, Mo:9.5% or below, W:9.5% or below, Cr:8.5% or below and Al:9.5% or below, and the total quantity of M when two or more kinds of M are contained is to be less than the prescribed percentage of the maximum value among each element contained in M) and the remainder substantially consisting of Fe. The alloy powder of average grain size of 0.3-80mum having the above-mentioned composition is molded, is sintered at 900-1,200 deg.C, and a heat treatment is performed at 350 deg.C or at the sintering temperature or below, thereby enabling to obtain the permanent magnet material having excellent magnetic characteristics. |
