Does a True Fatigue Limit Exist for Continuous Fiber‐Reinforced Ceramic Matrix Composites?

Abstract

The high‐cycle high‐frequency fatigue behavior of a Nicalon‐fiber‐reinforced calcium aluminosilicate ceramic composite was investigated. A key goal of the room‐temperature fatigue experiments was to determine if a true fatigue limit or endurance limit existed for this ceramic matrix composite. Although no fatigue failures occurred beyond 10 7 cycles, the stress–strain hysteresis modulus and frictional heating continued to change up to 10 8 cycles, at which point the 200 Hz experiments were terminated. This suggests that fatigue damage continued to evolve and that a true fatigue limit may not exist in ceramic matrix composites that have undergone interfacial frictional sliding.