| 摘要 |
PURPOSE:To ensure large coercive force for an R-Co-Fe-Cu-Zr alloy having a specified compsn. even in case of <=6% Cu content and >25% Fe content by subjecting the alloy to sintering, soln. heat treatment and two-step aging under specified conditions. CONSTITUTION:A magnet alloy consisting of, by weight, 22-27% R (one or more kinds of rare earth elements including Y), 12-35% Fe, 2-6% Cu, 1-4% Zr and the balance Co is continuously heated from 1,000-1,150 deg.C to 1,150-1,250 deg.C by >=30 deg.C at 0.1-10 deg.C/min heating rate and the alloy heated to 1,150-1,250 deg.C is isothermally sintered. The sintered alloy is subjected to soln. heat treatment at 1,100-1,245 deg.C. This treatment temp. is below the sintering temp. by 5-50 deg.C. The alloy is then subjected to isothermal treatment at 400-900 deg.C as first-step aging, isothermal treatment at 700-1,000 deg.C as second- step aging and continuous cooling to 300-600 deg.C at 0.2-10 deg.C/min cooling rate. The aging temp. is made higher in the second step than in the first step. |
