Modeling and Simulation of Ceramic Matrix Composite (CMC) Processing by Polymer Infiltration and Pyrolysis

ABSTRACT: The challenge for manufacturing ceramic matrix composites using the preceramic polymer infiltration and pyrolysis (PIP) method is to ensure a fully dense matrix. Material loss during a pyrolysis cycle requires multiple reinfiltration and pyrolysis cycles to maximize matrix density. While the first cycle typically uses a ceramic powder filled polymer, subsequent cycles do not. We propose to team with Teledyne Scientific, both to access measured data on fiber placement in tested CMC"s and to have a team member ready to benefit from knowledge learned here to improve the reliability of CMC"s for hypersonic application. The two-fold approach we propose uses a physical analog of CMC PIP processing to understand the PIP process. We propose to use photopolymer additive manufacturing to build multiple identical models of a preform that has stochastically varied fiber placement, and then studying their infiltration using poly vinyl alcohol in aqueous solution. Subsequent evaporation of the solvent will mimic the volume reduction associated with pyrolysis. Guided by such a physical observation of the PIP process, we will work with Teledyne to mathematically model preform geometry and the subsequent polymer infiltration and pyrolysis, such that matrix filling of an actual ceramic fiber preform can be optimized. BENEFIT: A model that can optimize matrix filling for a polymer infiltration and pyrolysis (PIP) processed CMC will be applicable to all CMC systems manufactured by PIP, as well as the CMCs of interest to our partner, Teledyne Scientific.