| 摘要 |
PURPOSE:To enhance the coercive force of a magnet made of a R2M17 type rare earth element by a method in which the magnet is sintered and then subjected to a heat treatment under a specific condition. CONSTITUTION:An alloy, consisting of 20-34wt% one or more of Y, Sc, La, and 17 elements of 58-71 atomic numbers as rare earth elements(R), the main components such as transition metals, e.g., Fe, Ni, Mn, Cr, Co, Ti, Zr, Hf, W, etc., the elements of Vb, VIb, VIIb, and VIII groups, or Cu, Ag, and other elements, is prepared by melting. The alloy fine powder of a grain size of 10mu or less is molded by pressing in a magnetic field of 5,000-15,000 oersted, degassed at 800-950 deg.C, and then sintered at 1,000-1,3000 deg.C. Then, the sintered ally is subjected to a solutionizing treatment, rapidly cooled to room temperature, and then subjected to an aging heat treatment at 800-950 deg.C. Then, the alloy so treated is gradually cooled at a cooling rate of 150 deg.C-10 deg.C/hr, but rapidly cooled in a temperature range of 700- 500 deg.C on the way, and then gradually cooled to room temperature. |
