| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rare earth sintered magnet satisfying both suppression in grain growth and densification by shortening the sintering time, and to provide its production process. <P>SOLUTION: When a rare earth sintered magnet is produced by sintering a molding of material alloy fine powder containing a rare earth element, a transition metal element and boron, de-binding process is performed by ohmic-resistance heating and then sintering is performed by high frequency induction heating. De-binding process is carried out efficiently by employing indirect heating through high frequency induction. Furthermore, temperature control of the molding is facilitated by employing direct heating through high frequency induction in sintering and the sintering pattern can be controlled arbitrarily. Consequently, dencification is accelerated while suppressing grain growth and unusual appearance, and low carbon and low oxygen are also realized. It is also advantageous in respect of equipment and cost. When sintering is performed by high frequency induction heating, quantity of oxygen contained in the material alloy fine powder is set not higher than 2,500 ppm. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
