Simulation Study on Reaction Characteristics and Deposition Process of SiC Coating Prepared by Chemical Vapor Deposition

In order to provide theoretical support for the process optimization and preparation of SiC intermediate layer in high-temperature oxidation resistance composite coating system, the reaction characteristics and deposition process of SiC coating prepared by chemical vapor deposition technology were simulated using COMSOL software and Reax FF software, that based on the finite element principle and the molecular dynamics simulation principle, respectively. The results indicated that the chemical vapor deposition process of SiC coating include the diffusion process and the thermal decomposition reaction process of precursor trichloromethylsilane （CH₃SiCl₃）. The SiC coating does not grow during the diffusion process, it only starts to grow from the thermal decomposition reaction process after 10⁻⁴ s, that is accompanied with the dissociation process of SiC coating. With the increase of incident particle energy, the number of Si and C particles deposited on the substrate surface per unit time continuously increases. Increasing the incident energy of particle is beneficial to improve the density of SiC coating. The uniform growth of SiC coating can be achieved when the incident energy of particles is higher than 2 eV. However, the number of dissociated Si and C particles increases when the incident energy is higher than 6 eV, which is not conducive to the deposition of SiC coating. In summary, the comprehensive properties of SiC coating prepared by chemical vapor deposition technology are the best when the incident energy is 3 eV.