Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

This study investigates the decomposition mechanism of Methyl trichlorosilane during Silicon Carbide (SiC) deposition during Chemical Vapor Infiltration (CVI). High-performance applications require SiC-based ceramic matrix composites (CMCs); however, producing them presents difficulties due to limited deposition rates, high energy consumption, and uneven coatings. To overcome these challenges, the mechanism of SiC formation must be understood completely. Modeling surface reactions of MTS decomposition on the SiC substrate using density functional theory (DFT) calculations with the Vienna Ab initio Simulation Package (VASP) is the key point of current research. By focusing on the adsorption, reaction, and desorption mechanisms that control SiC development, our method incorporates quantum mechanical models such as Kohn-Sham equations, the Many-Body System, Born-Oppenheimer (BO) approximation, and Generalized-Gradient Approximation (GGA). Using Transition State Theory (TST) and Potential Energy Surface (PES) mapping, the study investigates reaction routes and discovers important intermediates, such as methyl (CH₃) and other hydrocarbon species. We also emphasize the function of hydrogen in surface stabilization. The findings expand our knowledge of the rate-limiting steps in MTS breakdown and offer guidance for refining CVI/CVD procedures, which could increase material quality and deposition efficiency for cutting-edge engineering applications.

Document Type

posters

Language

English

Rights

http://rightsstatements.org/vocab/InC/1.0/

License

http://creativecommons.org/licenses/by/4.0/

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Quantum Mechanical Insights into Heterogeneous Surface Reactions in Chemical Vapor Infiltration

This study investigates the decomposition mechanism of Methyl trichlorosilane during Silicon Carbide (SiC) deposition during Chemical Vapor Infiltration (CVI). High-performance applications require SiC-based ceramic matrix composites (CMCs); however, producing them presents difficulties due to limited deposition rates, high energy consumption, and uneven coatings. To overcome these challenges, the mechanism of SiC formation must be understood completely. Modeling surface reactions of MTS decomposition on the SiC substrate using density functional theory (DFT) calculations with the Vienna Ab initio Simulation Package (VASP) is the key point of current research. By focusing on the adsorption, reaction, and desorption mechanisms that control SiC development, our method incorporates quantum mechanical models such as Kohn-Sham equations, the Many-Body System, Born-Oppenheimer (BO) approximation, and Generalized-Gradient Approximation (GGA). Using Transition State Theory (TST) and Potential Energy Surface (PES) mapping, the study investigates reaction routes and discovers important intermediates, such as methyl (CH₃) and other hydrocarbon species. We also emphasize the function of hydrogen in surface stabilization. The findings expand our knowledge of the rate-limiting steps in MTS breakdown and offer guidance for refining CVI/CVD procedures, which could increase material quality and deposition efficiency for cutting-edge engineering applications.