| 摘要 |
PURPOSE:To stabilize a reduction ratio by a method wherein, when an oxide permanent magnet is baked finally, it is baked at a temperature-rise rate of 0.1 to 10 deg.C/min at an initial baking stage at 70 to 99% with reference to a maximum temperature. CONSTITUTION:Fe2O3 and MO (where M is one out of Sr, Ba and Ca) are mixed. This mixture is baked temporarily; it is crushed fine to a prescribed grain-size distribution. It is baked fixedly in a magnetic field at a temperature- rise rate of 0.1 t 10 deg.C/min at an initial baking stage at 70 to 90% of a maximum temperature. When the temperature-rise rate is made fast, the contraction rate of an easy axis of magnetization is reduced and the contraction rate of a hard axis of magnetization is increased. When the temperature-rise rate is made slow, the contraction rate of the easy axis of magnetization is increased and the contraction rate of the hard axis of magnetization is reduced. Since the contraction rate can be controlled easily, the contraction rate can be stabilized. |
