Micro modeling of reactive melt infiltration for SiC/SiC ceramic-matrix composites

To simulate the manufacture of SiC/SiC ceramic-matrix composites (CMCs) by reactive infiltration, this paper presents a micro model of the infiltration of liquid silicon in carbon-coated SiC fiber preforms. A closed form solution to the radial mass transfer problem with chemical reaction in a cylinder is presented. At the micro level the equations of momentum, heat and mass transfer are numerically solved for a: representative volume element (RVE) of the preform, assumed to be a hexagonal army of carbon fibers. The analytical results provide insight into the diffusion controlled growth of the SiC layer on the fibers after chemical reaction. Results from the numerical study indicate that the decrease in porosity in the RVE after 0.7 mu s is about 10%.