Reactive melt infiltration (RMI) process is promising method to fabricate SiC fiber-reinforced SiC matrix (SiC/SiC) composites. Melted metal (or alloy) is infiltrated into porous fiber preform, and matrix is formed by reaction between melts and carbon. Quite complicated phenomena, such as interface reaction, crystal growth at the interface, and infiltration of metal (or alloy) media, occur in the process of matrix formation. Various works have been carried out to simulate multiphysics phenomena in RMI process, however, conventional analysis for liquid alloys during infiltration may not provide accurate information.
In the present study, the model was developed based on micro-scale. Simultaneously, the formation of SiC on the wall due to chemical reaction was incorporated into the simulation. The simulation results showed that the infiltration velocities were apart from the experimental results. The velocity obtained from simulation is 104 times higher than that of experimental result. It is comparable to numerical value using the model under assumption of Poiseuille flow, suggesting that the Si wetting velocity must be considered to explain the discrepancy from the actual phenomena. Infiltration of Si melts into the preform could not be treated by a simple fluid equation. We also carried out molecular dynamics simulation of wetting, and the results showed poor wetting when the substrate was graphite, but good wetting when the substrate was SiC. This suggests that it is important for the substrate to be SiC in the wetting of Si.