| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a valve member whose mechanical property such as strength and destruction toughness and heat shock resistance are improved. <P>SOLUTION: The valve member for liquid formed of a silicon nitride sintered body has a groove or a hole portion as at least part of a liquid flow path. The silicon nitride sintered body forming the valve member has a crystal phase containing silicon nitride as a main component, and a grain boundary phase containing a first metal silicide of a first metal element of at least one type of Fe, Cr, Mn, Co, Ni, Ti, Zr and Cu and a second metal silicide of a second metal element having a higher melting point than the first metal element. The density of each of the first metal silicide and the second metal silicide on the surface of the groove or the hole portion is lower than that of the inside of the silicon nitride sintered body. <P>COPYRIGHT: (C)2007,JPO&INPIT |
