Modeling the Effect of Oxidation on Damage in SiC/Ti-15-3 Metal Matrix Composites

In this paper, a micromechanical analysis is performed on a single ply continuous fiber SiC/Ti-15V-3Al-3Sn-3Cr (Ti-15-3) metal matrix composite to study the complex interactions between the composite microstructural components and the surrounding environment at high temperatures. Finite elements are incorporated to model oxygen diffusing into the free suface of a representative volume element (RVE) during cool down from the processing temperature. The resulting residual stress distribution is investigated assuming thermoelastic material models for the matrix, oxide layer, and fiber. Results indicate that the oxidized surface layer is prone to cracking upon subsequent mechanical loading, and this effect is strongly temperature dependent.