RARE EARTH MAGNET MATERIAL FOR ISOTROPIC BOND MAGNET

摘要

PROBLEM TO BE SOLVED: To provide a new rare earth magnet material for an isotropic bond magnet which is provided with satisfactory dimensional precision and high magnetic properties.;SOLUTION: The rare earth magnet material for an isotropic bond magnet has a main componential composition expressed by R_αT_{100-(α+β+γ+δ)}M_βB_γN_δ in atomic% (R is one or more kinds of rare earth elements including Y, and definitely comprises Sm; T is Fe or Fe and Co; M is one or more kinds of metals selected from Al, Ti, V, Cr, Mn, Cu, Ga, Zr, Nb, Mo, Hf, Ta and W, and definitely comprises Ti; and 5≤α≤18, 0.5≤β≤10, 0.1≤γ≤4, and 4≤δ≤30 are satisfied). The magnetic material uses a master alloy whose components are controlled so as to be the main componential composition of the above rare earth magnet material after nitriding, and obtained by performing molten metal rapid cooling with rolls for cooling at a peripheral speed of 0.05 to 10 m/s. The magnetic material consists substantially of a hard magnetic phase with a 2-17 type structure having a mean crystal grain size of 0.01 to 1 μm, and also the mean value of the area ratio of αFe is ≤5%.;COPYRIGHT: (C)2004,JPO