| 摘要 |
PURPOSE:To improve coersive force (iHc), a hysteresis rectangular ratio, and temperature characteristics by aging an alloy of a specific composition including chiefly Ce, Nd, and Pr under specific conditions. CONSTITUTION:An alloy is prepared, which comprises 5-15wt.% Sm, 8-20wt.% of one kind selected from a group Ce, Nd, and Pr, 10-30wt.% Fe, 2-10wt.% Cu, 1-5wt.% of one kind selected from a group Si, B, Ti, Ni, Cr, Zr, Hf, Nb, and Ta, substantially Co as a remaining fraction. The alloy lump is ground in N2 gas and resulting powder is formed by a transverse magnetic field into a product, which is then sintered. The sintered product is heated and maintained for three hours at most in a high temperature region higher than 750 deg.C, and aged where it is colled to a temperature of 400 deg.C over a time interval of 20hours or more. Hereby, a permanent magnet which has higher coersive force iHc and is excellent in all of a hysteresis rectangular ratio, a magnetized property, and temperature characteristics. |
