Numerical simulation for ICVI process of Si₃N_4p/Si₃N₄ composites

A mathematical model according to structural feature of Si₃N₄ particle reinforcement and process characteristic of isothermal chemical vapor infiltration (ICVI) was proposed to numerically simulate the densification behaviors of Si₃N₄ particle reinforced Si₃N₄ composites. The ball-like pore model is developed to depict the structure of Si₃N₄ particle reinforcement and the mass transfer equation of reagents is used to characterize the concentration profile in the preform. The corresponding experiment was done in order to testify the mathematical model. The calculated results represent the same densification regularity as the experimental data does, and the curves of calculated infiltration time and porosity are in agreement with the experimental ones, which indicates that the model developed here is reasonable to characterize the ICVI process of Si₃N_4p/Si₃N₄ composites.