| 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 and system. <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, sintering process is performed by high frequency induction heating under high vacuum where ultimate pressure is 10<SP>-4</SP>Pa or below. Since high frequency induction heating is employed in sintering, dencification is accelerated while suppressing grain growth and strange phase. Furthermore, since sintering is carried out under vacuum where ultimate pressure is 10<SP>-4</SP>Pa or below, the quantity of oxygen contained in the molding or the sintered molding is reduced sharply and the quantity of impurities is reduced. The production system comprises a sintering furnace which can be exhausted while containing the molding, and a coil connected with a high frequency power supply and performing high frequency induction heating of the molding wherein the coil is arranged on the outer circumference of the sintering furnace. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
