Advancing SiC Coatings of Short‐Fiber Using Triethylsilane: Insights from FB‐CVD Deposition Process

Abstract This study examines the use of triethylsilane (TES) as a non‐halogenated, less hazardous precursor in the Fluidized Bed ‐ Chemical Vapor Deposition (FB‐CVD) process for silicon carbide (SiC) coating on short fibers. It focuses on characterizing a pre‐matrix SiC layer over an interphase boron nitride (BN) coating, aiming to improve short‐fiber‐reinforced silicon carbide ceramic matrix composites (SiC/SiC CMCs). FB‐CVD is highlighted as a promising method for enhancing the applicability of discontinuous SiC/SiC CMCs. Advanced characterization techniquesScanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX), Auger Electron Spectroscopy (AES), X‐ray Photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM)—were used to analyze coated fibers. The findings reveal uniform, robust SiC coatings while preserving the BN layer. Notably, a stratified SiC structure, alternating between carbon‐rich and silicon‐rich zones, was observed. Auger spectroscopy and XPS provided insights into SiCx atomic composition and bonding environments. This research demonstrates TES's potential as an effective SiC precursor and advances understanding of FB‐CVD processes for short‐fiber coatings. The results pave the way for optimizing coating properties to enhance performance in SiC/SiC composites, opening new opportunities for further development.