Importance

Loading Importance Indicators...

Abstract

Provided are an anisotropic rare earth sintered magnet having a ThMn₁₂-type crystal compound as a main phase and exhibits good magnetic characteristics, and a method for producing it. The anisotropic rare earth sintered magnet has a composition of a formula (R_1-aZr_a)_v(Fe_1-bCo_b)_100-v-w-x-y(M¹_1-cM²_c)_wO_xC_y (where R is one or more kinds selected from rare earth elements and indispensably includes Sm, M¹ is one or more kinds of elements selected from the group consisting of V, Cr, Mn, Ni, Cu, Zn, Ga, Al, and Si, M² is one or more kinds of elements selected from the group consisting of Ti, Nb, Mo, Hf, Ta, and W, and v, w, x, y, a, b, and c each satisfy 7≤v≤15 at %, 4≤w≤20 at %, 0.2≤x≤4 at %, 0.2≤y≤2 at %, 0≤a≤0.2, 0≤b≤0.5, and 0≤c≤0.9), which contains a main phase of a ThMn₁₂-type crystal compound in an amount of 80% by volume or more with the average crystal particle diameter of the main phase being 1 μm or more, which contains an R oxycarbide in the grain boundary area, and which has a density of 7.3 g/cm³ or more. The production method for the anisotropic rare earth sintered magnet includes grinding an alloy that contains a ThMn₁₂-type crystal compound phase but does not contain an oxycarbide, then molding it in a mode of pressure powder molding with magnetic field application thereto to give a molded article, and thereafter sintering it at a temperature of 800° C. or higher and 1400° C. or lower to form an oxycarbide in the grain boundary area.

Loading the Abstract Image...

First Claim