材料期刊网

目的：研究吸波涂层因物理和化学损伤而导致的失效原因，用于评估吸波涂层的寿命，指导吸波涂层的功能结构优化，提高吸波涂层的使用寿命。方法通过高低温振动双结合、加速人工老化试验等方法和分析涂层失效前后的微观形貌、组成元素，对导致吸波涂层失效的多种因素进行试验验证。结果在固化阶段和高低温振动条件下，涂层因内应力变化导致开裂脱落；在紫外线照射和盐雾作用下，涂层因氧化和盐雾渗透导致粉化、鼓泡。结论建立了吸波涂层失效体系及失效因子，得到影响涂层实效的因素主要为：涂层厚度、附着力、致密度、有机成膜物功能键特性、吸收剂氧化活性等。在吸波涂层设计中，应采用低交联度树脂，降低因固化反应带来的内应力增加；通过减薄增韧，提高涂层的耐高低温交变和振动性能；通过设计耐腐蚀屏蔽层和在表面涂覆高耐侯保护层，提高吸波涂层在大气和介质腐蚀下的使用寿命。

ABSTRACT:Objective To study reasons of failure of absorbing coatings caused by physical and chemical damages so as to evalu-ate and improve the lifetime and guide the functional optimization of absorbing coatings. Methods A series of tests such as high-low temperature vibration and accelerated aging test, micro-topography of coatings before and after damage, and elementary analysis were taken to confirm the factors leading to failure in absorbing performance. Results During the solidification and high-low temper-ature vibration test, the performance failure was due to cracking and pealing caused by the change of internal stress. Exposed to UV and salt fog, the performance failure was due to pulverization and bubbling caused by coating oxidation and permeation of salt and fog. Conclusion According to the experiment results, the absorbing coating failure system and factors were established. The major factors that influenced the performance of coatings included coating thickness, adhesive force, density, functional groups of organic film forming substance and oxidative activity of absorbents. During the design of absorbing coatings, resin of low crosslinking de-gree should be used to reduce internal stress caused by solidification. Tolerance of high-low temperature shift and vibration can be enhanced by decreasing thickness and increasing toughness. The lifetime of coatings under atmospheric and medium corrosive con-dition was prolonged by introduction of corrosion resisting shielding layer and high weatherability protection layer.