セラミックスの疲労 (第4報)
常圧焼結窒化ケイ素の引張応力下の静的疲労挙動
1990 年 98 巻 1133 号 p. 83-92
詳細
1990 年 98 巻 1133 号 p. 83-92
The slow crack growth and creep characteristic of two intered silicon nitride ceramics under tensile stress were studied. The static fatigue strength degraded with increasing temperature due to the slow crack growth and the creep deformation. In slow crack growth failure without creep deformation, the power law for crack growth rate controlled the strength degradation under constant stress and/or constant stress rate. The modified Larson-Miller parameter was applicable to life prediction under static stress in creep deformation regime. The static fatigue behavior was mainly dominated by the grain boundary nature at elevated temperature. Crystallized phases at grain boundary inhibit not only slow crack growth by stress corrosion cracking but also cavity formation during creep deformation.
