| 摘要 |
PURPOSE:To improve molding compressibility by a method wherein a specific quantity of stearic acid is mixed with powder of an R2T14B group alloy consisting of a rare earth metal R and a transition metal T, and the powder is coated, compression-molded and sintered. CONSTITUTION:An ingot is prepared through high-frequency heating in an argon atmosphere so as to contain 34wt% Nd, 1.1wt% B and Fe as the remainder, and the alloy is crushed coarsely, and pulverized by a ball mill. A toluene solution is mixed with the powder so as to include 0-0.5wt% stearic acid, and the powder is coated, and dried. The powder for molding is pressure-molded in the same direction as an applied magnetic field to a discoid shape in the magnetic field of 8KOe. The molded shape is held for 1hr in a vacuum at 1,080 deg.C, held for 1hr in Ar, annealed up to 300 deg.C at a cooling rate of 100 deg.C/hr or less and quenched. The sintered body is held for 1hr at 500 deg.C, and quenched. Accordingly, magnet characteristics and compression moldability are improved, and high green density is obtained at low molding pressure, thus miniaturizing a molding equipment, then lengthening the life of a mold, etc. |
