摘要：辐射冷却无需外部能量输入即可实现高效散热，是一种航空航天领域理想的被动冷却技术，当前辐射冷却结构主要通过涂层技术或贵金属光刻工艺制备获得，其工艺复杂且难以适用于高温基底。本文提出采用飞秒激光脉冲线扫描式制造工艺，在耐高温基底材料表面，加工微米尺度狭缝阵列结构，利用狭缝轮廓表面偶极子震荡引起磁激元谐振机理，调控高温合金在8~14 μm波段的红外光谱发射率，实现航空热部件辐射冷却。利用傅立叶变换红外光谱法测得所制备结构的半球反射率，结果表征狭缝阵列的红外光谱发射率与仿真结果趋势一致：在 8~14 μm波段狭缝阵列结构较平坦表面红外光谱平均发射率提高了23 %。结合辐射冷却功率计算公式，理论计算得出加热功率为9 kW/m²时，狭缝阵列结构表面较平坦表面温度降低了约100 ℃。并且还探讨了飞秒激光脉冲加工参数对狭缝深度、轮廓表面的影响，此外该制造工艺有望实现低成本、高效率规模化高温结构辐射冷却器的生产。

Abstract: Currently, many photonic crystals and periodic patterned surface structure radiative coolers are prepared using precious metals (such as gold, platinum, and silver) or semiconductors (such as silicon, germanium, and gallium arsenide). Coupled with the expensive lithography process required for patterned surfaces, the high cost of manufacturing makes large-scale production impossible. This paper presents a novel method for achieving radiative cooling of thermal components in aircraft by creating a micron-scale groove array structure on high-temperature alloys using femtosecond laser pulse line scanning processing technology. The surface profile of the groove induces dipole oscillation, which causes a magnetic resonance mechanism that enhances the infrared spectral emissivity of high-temperature alloys in the 8~14 μm band. Then we use Fourier transform infrared spectroscopy to measure the hemispherical reflectance of the prepared structure. The results indicate that the trend of the infrared spectral emissivity of the groove array is consistent with the simulation results, particularly for the average infrared spectral emissivity of the groove array structure in the 8-14 μm band was increased by 23 %. Combined with the radiative cooling power formula, the theoretical calculation shows that the surface temperature of the groove array structure decreases by approximately 100 ℃ compared to the flat plate surface when the heating power reaches 9 Kw/m². The impact of femtosecond laser pulse processing parameters on the groove depth and surface profile is also discussed. Furthermore, this manufacturing process is anticipated to enable low-cost, high-efficiency and large-scale production of radiative coolers.

辐射冷却；狭缝阵列；磁激元谐振；飞秒激光脉冲加工