光学学报, 2011, 31 (8): 0814002, 网络出版: 2011-07-21
激光作用下环氧/硅树脂复合涂层的1.3 μm反射特性研究
Reflectance of Epoxy/Organsilicone Composite Coating at 1.3 μm under Laser Irradiation
激光光学 反射率 共轭反射计 复合涂层 热解 laser optics reflectance conjugated reflectometer composite coating pyrogenation
摘要
利用共轭反射计装置,开展了真空环境中激光作用下环氧/硅树脂双层结构复合涂层的1.3 μm反射特性研究,测量得到了涂层反射率随样品背表面温度的变化曲线。通过有限元分析和界面热阻修正得到了反射率随涂层温度的变化关系,探讨了反射率随温度的变化机理。研究结果表明,红外连续激光损伤环氧/硅树脂复合涂层,主要表现为底漆热解引发的鼓包分层和面漆热解导致的烧蚀变色;常温下涂层对1.3 μm激光的反射率约为0.80,激光辐照初始时变化不明显,鼓包前后出现波动,测量区涂层鼓包、烧蚀后反射率显著下降,最终保持在一个相对较低值;反射率变化与涂层热解过程、损伤方式密切相关,涂层对1.3 μm激光的反射率变化存在3个特征温度,分别对应底漆热解、面漆热解和表面状态趋于稳定时的温度。
Abstract
Experimental research on 1.3 μm reflectance of epoxy/organsilicone two-layer composite coating under infrared continuous-wave (CW) laser irradiation in vacuum is carried out. An experimental system for laser irradiation and reflectance measurement is set up with conjugated reflectometer. Results of signal detection theory (SDT) analysis indicate that heat deposition generated by laser makes pyrogenation of epoxy primer which leads to form and burst of bubbles and thermal ablation of topcoat. Heat transfer within coating-metal structure is simulated by finite element analysis procedure with interface thermal resistance modification, and the temperature-dependent reflectance is presented. Investigation results show that the change of reflectance is related to the modes of damage and processes of decomposition. 1.3 μm reflectance of epoxy/organsilicone coating is about 0.80 at room temperature, changes slightly at the very beginning of laser irradiation, decreases remarkably while bubbles burst and thermal ablation occurrs, and finally maintains a rather low level. There are three characteristic temperatures of reflectance evolution, the decomposition temperature of epoxy primer, the decomposition temperature of organosilicone topcoat, and the decomposition temperature when the reaction ends and the surface tends to be steady.
吴丽雄, 叶锡生, 王立君, 吴耀军, 刘卫平, 刘泽金. 激光作用下环氧/硅树脂复合涂层的1.3 μm反射特性研究[J]. 光学学报, 2011, 31(8): 0814002. Wu Lixiong, Ye Xisheng, Wang Lijun, Wu Yaojun, Liu Weiping, Liu Zejin. Reflectance of Epoxy/Organsilicone Composite Coating at 1.3 μm under Laser Irradiation[J]. Acta Optica Sinica, 2011, 31(8): 0814002.