| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a member for a molten metal composed of a silicon nitride-based sintered compact, which is excellent in mechanical properties and thermal shock resistance, is highly reliable, and can be used for a long period. <P>SOLUTION: The member for a molten metal is composed of a silicon nitride-based sintered compact having a columnar crystal 1 containing silicon nitride as a main component and a grain boundary phase 2 containing an oxide of a metal element as a main component. The silicon nitride-based sintered compact has open pores 3 on its surface; inside the open pores 3, a plurality of second columnar crystals 1b having a larger diameter than the first columnar crystals 1a present inside the silicon nitride sintered compact are present so as to entangle with each other. The erosion of the grain boundary phase 2 on the inner surface of the open pores 3 by the molten metal is suppressed, so mechanical properties and thermal shock resistance of the silicon nitride sintered compact itself can be improved. The molten metal less reacts with and attaches to the grain boundary phase 2, so the member for a molten metal can be used over a long period. <P>COPYRIGHT: (C)2012,JPO&INPIT |
