Multifunctional Ceramic Matrix Composites

Adding functionality to high temperature composites is increasingly becoming a requirement for a burgeoning number of aerospace applications. Conventional functional materials cannot survive the extreme conditions typically experienced during high-speed flight, and therefore more durable candidates must be considered. In this work, we investigate the integration of three refractory metals (W, Ta, Mo) into SiC/SiC composites, with the goal of complementing the purely structural composite with functionality unique to the metallic phases (e.g., electrical or thermal conductivity). To understand the onset and evolution of diffusion-based failure mechanisms, samples fabricated at low (1100 °C) and high (1700 °C) temperatures were analyzed with electron microscopy, X-ray diffraction, and Raman spectroscopy. Of the three metals, Ta and W showed the most promise for applications at extreme conditions.