Fatigue behavior of continuous fiber-reinforced ceramic-matrix composites (CFCCs) at room and elevated temperatures

摘要

Fabric orientation effects on the fatiguebehavior of Nicalon*/Al2O3 and Nicalon/SiC composites wereinvestigated by performing the mechanical tests at roomtemperature (RT) in air, and at 1,000oC in an argonenvironment. It was observed that the flexural-fatiguebehavior of the Nicalon/Al2O3 composite at ambient andelevated temperatures was significantly affected by theorientation of the loading direction to the fabric plies. Also,there was a significant reduction in the fatigue life on theNicalon/Al2O3 composite at 1,0000C, relative to that at RT. Incontrast, the fatigue behavior of the Nicalon/SiC compositewas not noticeably influenced by either the fabric orientationor the test temperature. The micromechanisms responsible forthe differences in the fatigue behavior of the Nicalon/Al2O3and Nicalon/SiC composites are elucidated in this paper.