| 摘要 |
PURPOSE:To improve the temperature characteristics in the residual magnetic flux density, the corrosion-resisting property and the coercive force of the title permanent magnet by a method wherein, after the alloy powder, contacting B and rare-earth elements including Y and the remaining part substantially composed of the transition metal elements such as Fe, Co and Ni, has been sintered, the sintered alloy powder is cooled down to room temperature, and then an aging treatment is conducted thereon. CONSTITUTION:The alloy powder containing Rem of 8-30% (Rem is the rare-earth element including Y), B of 2-20% and the remaining part substantially composed of the transition metal containing Fe, Co and Nd, the compounding quantity of which is 10-75% for Fe, 7-50% for Co, 1-30% for Ni, and 50-90% for Fe+Co+Ni. To be more precise, the molten alloy which has been adjusted into a suitable constituent composition is formed into an ingot, and then the ingot is pulverized into the grain diameter of several microns or thereabout. After the above-mentioned pulverized powder has been pressure-molded while an orientational treatment is being conducted in a magnetic field as occation demands, it is sintered and cooled down. When the molded body is cooled under control to room temperature at the cooling speed of 5-1000 deg.C/s within the temperature range from the sintered temperature to 300 deg.C. Then, an aging treatment is conducted at 300-700 deg.C in a vacuum atmosphere for 1-5 hours. |
