Mechanical properties of ultra-high temperature ceramic matrix composites (UHTCMCs): A review

Ultra-high temperature ceramic matrix composites (UHTCMCs) have comprised an important area of materials research and development for the last one and a half decades. The attraction of this class of materials stems from combining the desired mechanical, thermal, and oxidation properties of UHTCs with the superior damage and failure tolerance that CMC architectures can achieve. Of various reinforcement styles, the literature has reported widely on UHTC matrices containing whiskers, short fibers, and continuous fibers, particularly for carbon and SiC chemistries. Each reinforcement style presents unique processing and densification challenges, drastically affecting the mechanical properties that are observed in the fabricated composite. It is crucial to build a holistic understanding of the advantages and limitations of each composite type, to better streamline material and design selection for different extreme environment applications. This review addresses the history and recent advances in the development of UHTCMCs reinforced by whiskers, short fibers, and continuous fibers, paying specific attention to the process-dependent mechanical properties reported in the literature.