报告题目 (Title)：碳化硅复合材料及超高温陶瓷（Silicon Carbide Composites and Ultra-High Temperature Ceramics）
报告人 (Speaker)：Daejong Kim研究员（韩国原子能研究院）
报告时间 (Time)：2024年12月6日(周五) 10:00
报告地点 (Place)：校本部复合材料研究中心一楼会议室A101
邀请人(Inviter)：毛小东 研究员
主办部门：理学院纳米中心
报告摘要：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.
