汇报标题 (Title)：碳化硅复合伙料及超高温陶瓷（Silicon Carbide Composites and Ultra-High Temperature Ceramics）
汇报人 (Speaker)：Daejong Kim钻研员（韩国原子能钻研院）
汇报功夫 (Time)：2024年12月6日(周五) 10:00
汇报地址 (Place)：校本部复合伙料钻研中心一楼会议室A101
约请人(Inviter)：毛幼东 钻研员
主办部门：理学院纳米中心
汇报提要：SiC (Silicon Carbide) composites and UHTCs (Ultra-High Temperature Ceramics) are gaining significant attention in nuclear, aerospace, and space industries due to their excellent thermal and mechanical properties at high temperatures. In this study, high-purity SiCf/SiC composites were fabricated, and UHTC coatings were deposited using chemical vapor processes. Fiber preforms were prepared using high-purity, high-crystalline SiC fibers such as Tyranno SA3 and Hi-Nicalon Type S via filament winding. A pyrolytic carbon (PyC) interphase layer, approximately 200 nm thick, was uniformly deposited on the fibers using chemical vapor deposition (CVD). To prevent the formation of large pores, SiC nanowires were grown on the PyC-coated fiber preforms using CH3SiCl3 gas. Subsequently, the void spaces within the fiber preforms were filled with a SiC matrix derived from the same precursor using a forced-flow CVI (Chemical Vapor Infiltration) method to produce dense composites. For the deposition of transition metal carbide-based UHTC coatings, chlorinated precursors such as ZrCl4, TaCl5, and HfCl4, along with hydrocarbon gases (CxHy), were used as source materials in a low-pressure CVD process. High-density ZrC, HfC, and TaC with near-stoichiometric compositions were deposited. Their microstructural stability, mechanical strength, and stoichiometric ratios were evaluated.
