碳纳米线改性SiCf/SiCN复合材料的微结构调控与吸波机理

连续SiC纤维增强SiCN陶瓷基复合材料（SiCf/SiCN）基体呈无定形态、纳米异质界面少，对电磁波损耗能力不足，这是制约其应用的瓶颈。针对航空发动机对吸波型SiCf/SiCN复合材料的迫切需求，本项目拟采用催化聚合物浸渍裂解法（PIP），在SiCf/SiCN内原位自生碳纳米线，并构筑多尺度吸波界面。研究改性SiCf/SiCN复合材料的微结构设计与制备机理，以及碳纳米线对SiCf/SiCN复合材料吸波/力学性能的影响规律。基于催化PIP法探索制备新型碳纳米线改性SiCf/SiCN复合材料，揭示碳纳米线的生长机理和多尺度吸波界面的微结构调控机制，从宽频吸波设计的角度阐明碳纳米线改性SiCf/SiCN复合材料的电磁波损耗机理。本研究的成果有助于丰富SiCf/SiCN复合材料的电磁波吸收理论体系。

SiC fiber reinforced SiCN ceramic matrix composites with the amorphous substrate and little nano-heterogeneous interphase results in the insufficient electromagnetic wave absorption capability. The above problems limit their widely applications in broadband (8-18GHz) absorption fields. Focusing on the urgent needs of high thrust-weight ratio jet engine on SiCf/SiCN composites, the present proposal will develop a catalytic polymer infiltration and pyrolysis method (PIP). Carbon nanowires as a high quality absorbing agent will be in-situ formed by PIP method, so that muiti-scale absorbing interphase will be formed in the SiCf/SiCN compoistes to increase the polarization loss capability of matrix. The research contents include: the microstructure design and near-net fabrication mechanisms of carbon nanowires modified SiCf/SiCN composites; the influence of carbon nanowires on the electromagnetic wave absorbing properties and mechanical properties of SiCf/SiCN composites. We propose to fabricate a novel carbon nanowires modified SiCf/SiCN composites by in-situ catalytic PIP process at the temperature lower than 1000℃, and reveal the growth mechanism of carbon nanowires and the design rules of multi-scale absorbing interphase, and also clarify the electromagnetic wave absorbing mechanism of carbon nanowires modified SiCf/SiCN composites. The proposed research will enrich the electromagnetic wave absorbing theory of SiCf/SiCN compoistes.