CERAMIC MATRIX COMPOSITES (CMC): MANUFACTURING AND MICROSTRUCTURAL EFFECTS ON THE MECHANICAL PROPERTIES USING THE PARAMETRIC HFGMC

Advanced Carbon fiber-based Ceramic Matrix Composites (CMCs) are important in today`s aviation industry because of their unique properties. They can withstand high temperature and severe erosion conditions, while maintaining the composites strength at relatively lower weight.

These unique properties depend on the microstructure of the formed material through the CMC`s production process. The use of refined micromechanical methods, such as the parametric High Fidelity Method of Cells (HFGMC) is crucial in order predict the overall thermo-mechanical properties and how they are related to the optimal ratio of the phases, towards improving the desired and objective properties. Furthermore, applying this new micro-scale analysis can save time and money by replacing the experiments on such expensive material system. It can even generate added values that one cannot extrapolate in standard experimental approach such as predicting the overall anisotropic mechanical properties, and the stress states at the micro scales. It should be noted that all the inputs for the proposed micromechanical simulations can be easily obtained by using basic physical measurements combined with data in the open literature, such as material`s microstructure and phase`s properties.

This research presents a new framework for prediction the overall thermo-mechanical properties of CMCs using the parametric HFGMC starting from the manufacturing process of CMCs by Liquid Silicon Infiltration (LSI) method. For each production stage, a Repeated Unit Cell (RUC) model is applied in order to achieve more reliable results at each production level. The proposed micromodels are nested in a multi scale analysis in order to generate the overall effective properties of the CMC. Finally, the effects of material microstructural features on the overall elastic properties are investigated, reported and discussed.