窒化けい素の高温における疲労き裂伝ぱ機構および伝ぱ特性に及ぼす結晶粒径の影響

概要

論文の詳細を見る
Fatigue crack growth behavior of silicon nitride at room and high temperatures was investigated. Fatigue crack growth mechanism at high temperature and the effect of grain size on crack growth behavior were also discussed. Higher crack growth resistance of larger grain size material was observed both at room and high temperatures. Crack growth resistance was high in cyclic fatigue compared to static fatigue, while the cyclic loading accelerated crack growth rate at room temperature and resulted in lower crack growth resistance. High temperature fatigue cracks grow by the microcrack initiation and coalescence mechanism, which is similar to room temperature. Soften grain boundary glass phase at high temperature significantly influences fatigue crack growth resistance:the high shear deformation rate of soften glass phase induces high rheological resistance and consequently high crack growth resistance.
1997-05-15