金属纳米颗粒修饰的碳化硅纳米线吸波性能和界面结合强度研究

High-temperature microwave absorbing material is the key component to ensure the stealth performance of high-speed aircraft. SiC nanowires are potential structural functional integration material used for microwave absorption under high-temperature, however, it is urgent to further enhance their absorption performance. Therefore, this project intends to comprehensively investigated the controllable decoration of metal nanoparticles on the surface of SiC nanowires by the magnetron sputtering method, to clarify the effect of the metal species, particle size and deposition density on their dielectric properties. Then the effective method to enhance and modulate the absorption performance of SiC nanowires would be mastered. After that, the interfacial bonding strength between the metal nanoparticles and the SiC nanowires under harsh environment would be intensively studied and carefully described by simulating the mechanical shocks and the thermal shock of high-speed flight, and the influence mechanism of the possible interfacial damage on the absorption performance would also be discussed. It is expected this project would provide the experimental base and the theoretical guidance for developing high-temperature absorbing SiC materials used in high-speed aircraft, which has important academic value and broad application prospect.

高温吸波材料是保障高速飞行器隐身性能的关键材料。碳化硅纳米线作为潜在的结构功能一体化高温吸波材料，迫切需要进一步增强其吸波性能。因此，本项目拟采用磁控离子溅射，深入研究碳化硅纳米线表面金属纳米颗粒的可控修饰，掌握金属种类、颗粒粒径及沉积密度与其介电性能之间的关系规律，实现其吸波性能的增强与调控；模拟高速飞行将经受的机械振动冲击和反复高低温热冲击，深入研究并明晰该严苛条件下金属纳米颗粒与碳化硅纳米线之间的界面结合强度，以及可能存在的界面破坏对其吸波性能的影响机制，为碳化硅纳米线作为高温吸波材料，在高速飞行器上的应用提供实验基础和理论指导，具有重要的学术价值和广阔的应用前景。

吸波材料对高速飞行器的雷达隐身性能起决定性作用。当超高速飞行时其鼻锥帽、机翼前沿、进气道和尾喷管等部位的工作温度可达1000℃以上，常温下广泛应用的吸波材料，如碳材料、磁性吸波材料在耐高温性能和比重方面均难以满足高速飞行器的要求。而碳化硅纳米线是一种极具实用价值的高温吸波材料。但是，碳化硅纳米线作为一种典型的半导体材料，其电导率低、电导损耗弱，也不具备磁损耗性能。因此，其吸波性能与强电导损耗的碳纤维、碳纳米管以及强磁损耗的铁磁材料相比，仍然存在显著的差距。本课题通过磁控溅射方法在碳化硅纳米线分别沉积了Pt、Au、Ni等金属纳米颗粒，掌握了多种金属纳米颗粒表面修饰碳化硅纳米线材料的制备方法；分析了不同金属纳米颗粒修饰对碳化硅纳米线的介电性能、损耗机制、吸波性能的影响规律，通过优化修饰金属纳米颗粒种类和修饰量，使碳化硅纳米线在1-18GHz频段内的最小理论反射损耗达到–50.6dB，有效吸收频宽（RL≤–10dB）达到7.2GHz；通过模拟碳化硅纳米线经受热冲击和机械振动，阐明了金属纳米颗粒表面修饰碳化硅纳米线材料具有良好的界面结合强度，其介电性能基本未受到明显影响，表明其作为高温电磁波吸收材料具有良好的潜力。