Wang Chenyang, Yin Lexiang, Li Peng, Huang Qing
School of Materials Science and Chemical Engineering, Ningbo University, Ningbo 315211, China.
Zhejiang Key Laboratory of Data-Driven High-Safety Energy Materials and Applications, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Materials (Basel). 2025 Jun 4;18(11):2633. doi: 10.3390/ma18112633.
The incorporation of MAX phase interface layers into silicon carbide (SiC) composites has been shown to significantly enhance mechanical properties, particularly under irradiation conditions. However, conventional Ti-based MAX phases suffer from thermal instability and tend to decompose at high temperatures. In this work, an ScSnC coating was successfully synthesized onto the surface of SiC fibers (SiC) via an in situ reaction between metals and pyrolytic carbon (PyC) in a molten salt environment. The PyC layer, pre-deposited by chemical vapor deposition (CVD), served as both a carbon source and a structural template. Characterization by SEM, XRD, and Raman spectroscopy confirmed the formation of ScSnC coatings with a distinctive hexagonal flake-like morphology, accompanied by an internal ScC intermediate layer. By turning the Sc-to-Sn ratio in the molten salt, coatings with varied morphologies were achieved. ScC was identified as a critical intermediate phase in the synthesis process. The formation of numerous defects during the reaction enhanced element diffusion, resulting in preferential growth orientations and diverse grain structures in the ScSnC coating.
已表明将MAX相界面层引入碳化硅（SiC）复合材料可显著提高机械性能，尤其是在辐照条件下。然而，传统的钛基MAX相存在热不稳定问题，在高温下容易分解。在这项工作中，通过金属与热解碳（PyC）在熔盐环境中的原位反应，成功地在SiC纤维（SiC）表面合成了ScSnC涂层。通过化学气相沉积（CVD）预沉积的PyC层既是碳源又是结构模板。通过扫描电子显微镜（SEM）、X射线衍射（XRD）和拉曼光谱表征证实形成了具有独特六边形片状形态的ScSnC涂层，并伴有内部ScC中间层。通过改变熔盐中的Sc与Sn比例，获得了形态各异的涂层。ScC被确定为合成过程中的关键中间相。反应过程中形成的大量缺陷增强了元素扩散，导致ScSnC涂层中出现择优生长取向和多样的晶粒结构。
