Inhibited carbon-carbon composites: Isothermal and fatigue exposure

The oxidation process is examined under isothermal, cyclic thermal and thermomechanical fatigue conditions for inhibited carbon-carbon composites. Mass loss and material property degradation assessment is undertaken with subsequent exploratory nondestructive testing utilizing DMA and PUCOT techniques. An analytical diffusion model is developed to evaluate oxidation degradation for selected exposure conditions. The results are then compared with the experimental data generated. Nondestructive testing techniques introduced along with the diffusion model successfully trace the shear and axial modulus degradation of inhibited carbon-carbon composite as oxidation progresses. These results when compared with thermomechanical data establish the significance of the combined temperature and mechanical load on the overall material characterization of carbon-carbon laminates.