Continuous fiber-reinforced ceramic

Fig. 14. Failure mechanisms for continuous fiber reinforced ceramic matrices (58).

Domier has developed a production route for continuous fiber-reinforced ceramics based on the impregnation and pyrolysis of Si-polymers. This process is related to the manufacturing of fiber-reinforced plastics and allows the cost-effective production of large and complex CMC-structures. 

Following the multiple matrix cracking, the composite can continue to carry the load until fiber failure. The ultimate tensile strengths of several continuous fiber-reinforced ceramic composites versus temperatures are shown in Fig. 

Elevated Temperature Creep Behavior of Continuous Fiber-Reinforced Ceramics... 

Consider a continuous fiber-reinforced ceramic as a multiphase system where the individual phases are parallel to one another and to the uniaxial loading direction. The fibers (or fiber bundles), matrix, and interface zone are treated as individual phases. In general, each phase undergoes elastic-plastic (creep) deformation. In the present analysis, the creep rate of each phase, e is assumed to obey a general creep law of the following form... 

The model proposed by Rouby and Reynaud46 represents the first systematic approach for understanding how the microstructural damage governs the fatigue life of continuous fiber-reinforced ceramic matrix composites. This model will be used to explain various aspects of fatigue failure in the remaining portion of this chapter. 

Experimental studies of the influence of stress ratio on elevated temperature fatigue life have been conducted by Suresh71 for whisker-reinforced AI2O3 (see Chapter 7 by Suresh for a discussion of the fatigue behavior of whisker-reinforced ceramics). In this section, the influence of stress ratio on the fatigue life of continuous fiber-reinforced ceramic matrix composites is discussed. 

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