Numerical simulation for fabrication of C/SiC composites in isothermal CVI reactor

A two-dimensional mathematical model for fabrication of C/SiC composites in a hot-wall isothermal chemical vapor infiltration reactor was developed. Transport phenomena of momentum, energy and mass in conjunction with infiltration induced changes of preform structure were taken into account. The integrated model was solved by finite element method to numerically simulate flow field, temperature field, concentration field and densification behavior of C/SiC composites at a typical operating condition of isothermal CVI process. Calculated results shows that three different stages exist in densification behavior of C/SiC composites, that is, micro-pores infiltration dominated stage, mixture dominated stage and macro-pores infiltration dominated stage. Favorable agreement is then seen between calculated results and corresponding experimental data which implies that this mathematical model is valid and reasonable to characterize isothermal CVI process of C/SiC composites.