Nie Haifeng, Si Pingzhan, Ren Quanxing, Yin Ziqiang, Cao Tihao, Huang Zhengren, Huang Qing, Li Yinsheng
College of Materials Science and Engineering, China Jiliang University, Hangzhou 310018, China.
Zhejiang Key Laboratory of Data-Driven High-Safety Energy Materials and Applications, Ningbo Key Laboratory of Special Energy Materials and Chemistry, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
Materials (Basel). 2024 Nov 25;17(23):5765. doi: 10.3390/ma17235765.
This study investigated the influence of preformed composition and pore size on the microstructure and properties of SiC/SiC composites fabricated via reactive melt infiltration (RMI). The process began with the impregnation of SiC fiber cloth with phenolic resin, followed by lamination and pyrolysis. Subsequent steps included further impregnations with phenolic resin, SiC slurry, and carbon black slurry, each followed by additional pyrolysis. This process resulted in three types of preforms, designated as PP, PS, and PC. These preforms exhibited a multimodal distribution of pore size, with peak pore diameters around 5 μm for PP, ranging from 200 nm to 4 μm for PS, and approximately 150 nm for PC. The preforms were then subjected to molten silicon infiltration at 1600 °C under vacuum for 1 h to create SiC/SiC composites. The PP preform contained only pyrolytic carbon, leading to a composite with high closed porosity and unreacted carbon, resulting in poor mechanical properties. The PS preform, which was impregnated with SiC particles, displayed an optimized pore size distribution but retained significant amounts of residual silicon and carbon in the final composite. In contrast, the PC preform featured both an ideal pore size distribution and an adequate amount of carbon, achieving high density and low porosity with reduced residual phases in the final composite. This optimization led to a flexural strength of 152.4 ± 15.4 MPa, an elastic modulus of about 181.1 ± 0.1 GPa, and a thermal conductivity of 27.7 W/mK in the SiC/SiC composites product. These findings underscore the importance of preform optimization in enhancing the performance of SiC/SiC composites, potentially paving the way for more reliable nuclear fuel cladding solutions.
本研究调查了预制体组成和孔径对通过反应熔体浸渗（RMI）制备的SiC/SiC复合材料微观结构和性能的影响。该过程始于用酚醛树脂浸渍SiC纤维布，随后进行层压和热解。后续步骤包括用酚醛树脂、SiC浆料和炭黑浆料进一步浸渍，每次浸渍后再进行热解。这个过程产生了三种类型的预制体，分别命名为PP、PS和PC。这些预制体呈现出多峰孔径分布，PP的峰值孔径约为5μm，PS的峰值孔径范围为200nm至4μm，PC的峰值孔径约为150nm。然后将预制体在1600℃真空下进行熔融硅浸渗1小时，以制备SiC/SiC复合材料。PP预制体仅含有热解碳，导致复合材料具有高闭孔率和未反应的碳，从而使其力学性能较差。浸渍了SiC颗粒的PS预制体显示出优化的孔径分布，但在最终复合材料中保留了大量的残余硅和碳。相比之下，PC预制体具有理想的孔径分布和适量的碳，在最终复合材料中实现了高密度、低孔隙率以及减少的残余相。这种优化使得SiC/SiC复合材料产品的弯曲强度为152.4±15.4MPa，弹性模量约为181.1±0.1GPa，热导率为27.7W/mK。这些发现强调了预制体优化对于提高SiC/SiC复合材料性能的重要性，可能为更可靠的核燃料包壳解决方案铺平道路。
