热循环对某热控涂层热辐射的影响

Thermal Cycling Effect on Thermal Radiation Properties of One Type of Thermal Control Coatings

对某热控涂层进行了快速高低温循环试验（-196 ～900℃）,通过太阳吸收比、半球发射率检测和SEM形貌等对涂层的热辐射性能进行分析.实验表明,经过热循环后,该涂层保持高吸收比的稳定状态（0.87左右）,而半球发射率从原始的0.57提高到0.72,最后稳定在0.75左右.SEM微观形貌研究表明,热循环实验使涂层表面的结晶度和晶粒大小发生变化,导致涂层热辐射性能改变.

We investigated the thermal radiation properties of one type of thermal control coatings with stainless steel as substrate under thermal cycles. The rapid thermal cycles ranged from -196℃ to 900℃. Solar absorptance, hemispheric emittanee and SEM were measured for analyzing the thermal radiation properties of the coatings. The re- sults show that solar absorptance of the thermal control coating had little change under thermal cycles, while the cycles had obvious effect on hemispheric emittance of the coatings, which increased from 0.57 to 0.72, and finally the hemi- spheric emittance was steady at 0.75. According to SEM, the surface of the coating was better crystallized under ther- mal cycles, and the grain size on the surface of the coating was bigger. The difference of microstructures on the sur- faces of coatings leads to the changes of thermal radiation properties.