CHALLENGING CERAMIC-MATRIX COMPOSITES FOR APPLICATIONS IN SEVERE ENVIRONMENTS

Non-brittle ceramic matrix composites (CMCs) consisting of a ceramic m atrix reinforced with continuous fibers, such as the SiC/SiC composite s, exhibit outstanding mechanical properties, when properly processed. Tensile failure stress as high as 400 MPa, tensile failure strain clo se to 1% and energy release rate of the order of several 10 KJ . m(-2) are currently achieved for 2D-SiC/PyC/SiC. The main subject of concer n is probably the effect of oxidizing environment under loading. The p resent status of knowledge and further improvements of the materials a re presented and discussed.