Numerical simulation and experimental validation of ICVI-C/C reaction process by methane/propane gas mixture source

This study aimed to optimize the preparation of carbon/carbon (C/C) composites by developing and validating a computational model for three-dimensional (3D) transient densification through an isothermal chemical vapor-phase infiltration (ICVI) process using a methane/propane mixture. Simplified multistep parallel reaction kinetics were employed to simulate the pore evolution using a two-dimensional representative volume element model and a 3D stochastic fiber model. The permeability, flow modeling, and material transfer behaviors were calculated using the Ergun, Brinkman, and mixing diffusion equations. The density was calculated to be 1.294 g/cm3 after 50 h of deposition with specific flow rates and temperatures. The experimental densities were lower than those predicted with an increased propane flow, highlighting the complex reaction kinetics. The numerical simulation results exhibited strong agreement with the experimental results at 1328 K, achieving a correlation of up to 5.918. This study provides a robust theoretical and experimental basis for optimizing the structure and process control of C/C composites.