Technical Papers and Presentations

The excessive presence of residual SiC matrix inter-fiber pores is often the main cause for the very poor mechanical strength and toughness of SiC/SiC composites manufactured by CVI (Chemical Vapour Infiltration) process. This work presents a micro/macro Microwaveassisted Chemical Vapour Infiltration (MW-CVI) model as a strategy to attack the problems above. The proposed model couples a reactor-scale (macro) steady state electromagnetic MWheating/heat conduction model with a pore-scale (micro) transient gas diffusion-flow/densification kinetic model. A sensitivity analysis is first accomplished to identify the most critical parameters playing a role in the MW-CVI process. Second, the densification process of the SiC/SiC composite is investigated in detail. The results show that the MW frequency is, among others, the most critical factor affecting the MWCVI process.