R-Curve Behavior and Fatigue

With the increase in testing temperature, the fatigue thresholds for both microstructures decrease slightly up to 1100°C. At 1200°C, which is above the brittle-to-plastic transition (see below), the da/dN versus AK curves showed three distinctive regions that were more pronounced for the fine-grained samples [132]. 

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Miyajima T, Sakai M, Fibre pullout and fracture energy of C-fibre/C-matrix composites, Bradt RC, Hasselman DPH, Munz D, Sakai M, Ya Shevchenko V, Fracture Mechanics of Ceramics 9, Composites, R-Curve Behavior and Fatigue, Japan Fine Ceramics Center, Proc 5th Int Symp, Nagoya, Jul 15-17 1991, Plenum, 83-95, 1992. 

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