Assessment of Oxidation in Carbon Foam

Carbon foams exhibit numerous unique properties which are attractive for light weight applications such as aircraft and spacecraft as a tailorable material. Carbon foams, when exposed to air, oxidize at temperatures as low as 500-600 degrees Celsius. The research objectives of this study are to assess the degree of oxidation of carbon foam by experimental and computational methods and evaluate the degradation in stiffness of the bulk foam as a function of oxygen concentration profile, time and temperature. In parallel to simulation, oxidation tests are conducted to observe changes in morphology and to calculate the apparent activation energy. Degradation patterns in the carbon foam microstructure are categorized through optical microscopy (OM) images post oxidation. The influence of microstructure and temperature on the oxygen concentration profile is investigated in parametric models with varying porosity. The degradation in bulk foam stiffness is found to be strongly dependent on the temperature and non-uniform oxygen concentration profile. The overall results enhance the design of experiments for high temperature and oxidative environments, illustrating the relationship between foam microstructure and oxygen concentration in porous media.