Modeling the Environmental Effects on Carbon Fibers in a Ceramic Matrix at Oxidizing Conditions

Oxidation microstructure studies of reinforced carbon/carbon

“…5(a). Note that attack, as evidenced by thinning of the fiber bundles, is uniform throughout the entire width of the specimen, suggesting reaction control of the oxidation process [9]. Fig.…”

“…The conclusions from oxidation studies of carbon fiber/SiC matrix composites [8,9] are also useful in understanding oxidation of RCC. Halbig and Cawley [9] show that reaction control at 750 o C leads to more uniform attack deep into the substrate; whereas diffusion control at 1250 o C leads to attack around the edges of the specimen.…”

“…Halbig and Cawley [9] show that reaction control at 750 o C leads to more uniform attack deep into the substrate; whereas diffusion control at 1250 o C leads to attack around the edges of the specimen.…”

High-temperature fatigue behavior of SiC-coated carbon/carbon composites in oxidizing atmosphere

“…These kinds of microstructural morphologies are mainly caused by the diffusion controlled oxidation kinetic. 12 The carbon is very reactive at the present experiments and consumes oxygen as soon as it is supplied so that the interior becomes deprived of oxygen. A shrinking core effect is seen as the reaction front moves inward.…”

Modeling the Effect of Oxidation on Tensile Strength of Carbon Fiber−Reinforced Ceramic−Matrix Composites

“…The carbon fiber within the silicon carbide matrix oxidized very differently depending on whether or not the composite was subjected to stress, i.e., without a stress, the material became self-protected at temperatures from 900 to 1400°C due to crack closure; with the increase of stress from 69 to 172 MPa, the failure time reduced 67−82 % at temperatures from 750 to 1500°C. Halbig et al [6][7][8] developed a finite difference model to simulate the diffusion of oxygen into a matrix crack bridged by an array of carbon fiber tows. The effects of temperature, diffusion coefficient, reaction rate constant, geometry and environment have been investigated.…”