原子氧与紫外综合辐照对Kapton/Al性能的影响

Surface Microstructures and Properties of Kapton/Al Coatings Irradiated by Atomic Oxygen and Ultraviolet

Kapton/Al薄膜二次表面镜是一种广泛应用的热控涂层,用于维持航天器表面正常的工作温度。本文利用激光源原子氧设备对Kapton/Al薄膜二次表面镜进行了原子氧与紫外综合辐照试验,试验前后通过高精度微量天平、扫描电镜、紫外-可见-近红外分光光度计及X射线光电子能谱仪等测试分析手段观察了材料质量损失、表面形貌、光学性能随辐照时间的演化规律,分析了试验前后Kapton/Al薄膜二次表面镜表面成份的变化。结果表明:Kapton/Al薄膜二次表面镜的质量损失随辐照时间的增加呈线性增大,原子氧与紫外综合辐照造成的质量损失明显高于单独原子氧作用产生的质量损失;试验后试样表面呈"地毯"状形貌,且随辐照时间的增加表面粗糙度变大;Kapton/Al薄膜二次表面镜的光谱反射系数随综合辐照时间的增加而降低,致使太阳吸收比的变化不断增大;试验后试样表面成份变化明显,说明原子氧和紫外环境与Kapton/Al薄膜二次表面镜表面发生了复杂的物理化学作用。

The effect of the atomic oxygen（AO） and ultraviolet（UV） irradiation on the microstructures and proper- ties of Kapton/Al second surface mirror, a thermal control coating for keeping equilibrium temperature of the spacecraft exterior surfaces in low earth orbit（LEO） environment was investigated by ground simulationtest test. The irradiated surfaces of Kapton/Al coatings were characterized with high precision micro-balance, scanning electron microscopy, UV/Vis/ NIR spectrophotometer and X-ray photoelectron spectroscopy. The results show that the AO and UV irradiation has a major impact on the surface roughness and reflectance of the Kapton/Al coatings. For instance, as the irradiation time increased, the mass loss and sm＇face roughness linearly increased and the reflectance decreased, accompanied by an increased solar absorptance;when it comes to surface damages, the combined AO and UV irradiation outperforms the AO irradiation. In addition, the complicated contents observed on the surfaces indicate a series of the irradiation-induced chemical reactions.