Effect of microstructural features and properties of constituents on the thermo-elastic properties of ceramic matrix composites

It is proposed that the effect of microstructural features and constituents on thermo-elastic properties in ceramic matrix composites (CMCs) can be identified by using descriptive modeling tools. In this work, three CMC materials – N720/AS, SiC/SiNC and SiC/SiC-B4C, were modeled and tested. A hybrid FEA code was used to calculate thermo-elastic properties as a function of porosity, constituent volume fraction, and fiber coating thickness. Model inputs were obtained from properties of as-manufactured composite constituents (when possible), literature values of constituent materials, and quantitative microscopy. The results illustrate the sensitivity of the composites' physical properties to the microstructural features of interest and demonstrate a way of using modeling tools when critical input values are not available.