Mathematical modelling of microwave-enhanced chemical vapour infiltration

With their excellent high temperature mechanical, chemical and thermal properties, fibre reinforced ceramic matrix composites have emerged as an important class of materials having a wide range of applications in various technological fields. Microwave Enhanced Chemical Vapour Infiltration (MECVI) has been recognized as a new process route because of its ability to conserve the reliability and durability of the precursor materials. The primary advantage of using microwaves is that they cause an inverse temperature profile to be formed that prevents entrapment of accessible porosity and greatly accelerates the process. However, to develop the MECVI process further, a complete understanding of the effects of the process parameters on the infiltration mechanism and processing time is necessary. Modelling efforts can offer an insight into the critical factors in this process and suggest ways to optimize processing. A 2-D mathematical model investigating the densification of SiCf/SiC composites by microwave enhanced Chemical Vapour Infiltration (CVI) under forced-flow of the gaseous reactants is presented. [Continues.]