| 摘要 |
PURPOSE:To provide a sintered silicon nitride having excellent fatigue characteristics and high toughness. CONSTITUTION:The objective sintered silicon nitride is composed of a crystalline phase consisting of silicon nitride and a grain boundary phase containing rare earth element and aluminum element. The length of the major axis of the silicon nitride crystal particle is <=10mum and that of the minor axis is <=2mum. The areal ratio of the silicon nitride crystal particle having an aspect ratio of >=3 is >=15% determined by the two-dimensional analysis of a cut surface. The sintered compact has a fracture toughness of >=6MPa.m<1/2>. |
