| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a dense silicon nitride sintered compact having a fine structure even in small grain boundary phase component and excellent wear resistance. <P>SOLUTION: The silicon nitride sintered compact comprises crystalline particles of silicon nitride, an amorphous grain boundary phase containing a group III element in periodic table, aluminum, magnesium, silicon, oxygen and nitrogen and a group VI element compound in periodic table which is dispersed in the grain boundary phase and contains ≥0.1 mass% group III element expressed in terms of oxide, 0.05-0.5 mass% aluminum expressed in terms of oxide, ≥0.3 mass% magnesium expressed in terms of oxide, ≤2.5 mass% in total of the group III element, aluminum and magnesium (which are expressed in terms of oxide), 0.1-2 mass% group VI element compound expressed in terms of oxide and ≤1.3 mass% oxygen. <P>COPYRIGHT: (C)2008,JPO&INPIT |
