摘要
针对湿热、高氯环境中的微波吸收材料性能失效问题,开展了吸波涂层在海水腐蚀过程中的表面状态、微波反射率、电磁参数随海水腐蚀时间的演变研究。研究结果表明,在高氯海水的介质中,吸波涂层中铁磁性吸收剂会发生电化学腐蚀行为,腐蚀产物以涂层中磁性吸收剂为发散点,在涂层中向外扩散,并随着疏松性腐蚀产物的堆积,逐渐从涂层中脱落。海水中Cl^(-)在涂层中的渗透和扩散,促进了水合氧化铁等腐蚀产物的生成,并从涂层中带走部分Fe^(2+),降低了涂层中功能材料的有效成分含量。铁磁性吸收剂的腐蚀性行为致使吸波涂层的介电常数、磁导率、电磁损耗随着腐蚀时间的增加,均呈现下降的趋势,其在2.0~18.0 GHz频段内的吸波性能逐渐下降,最终导致吸波涂层的失效行为。通过分析吸波涂层在湿热、高氯环境中的电磁特性演变规律,为解决在海水腐蚀环境中因吸收剂变质导致的涂层吸波性能失效问题奠定了理论基础。
Microwave absorbing materials long-term service in hygrothermal and high chloride environments were constantly faced with the failure of absorbing properties, which seriously threatened the viability of military equipment. With the purpose of solving the failure problem of microwave absorption performance, the surface states and the main production characteristics in the microwave absorbing coatings were systematically analyzed by means of chemical analysis, microscope analysis, scanning electron microscope(SEM) and energy dispersive analysis(EDS). In addition, the reflectivity characteristics and the electromagnetic parameters of the microwave absorbing coatings in the process of seawater corrosion in the range of 2.0~18.0 GHz were analyzed by means of network analysis and free space method. Afterwards, the evolution of the absorbing properties and electromagnetic characteristics in the process of seawater corrosion was educed. The results showed that the ferromagnetic absorbers in absorbing coatings expressed electrochemical corrosion behavior in the medium of high chloride seawater. Due to the particle size of the absorbent in the coating, the interface effect between absorbent and resin was evident, and loose acicular corrosion products accumulated around the absorbent and the crack between the absorber and the substrate in the corrosion pit became larger, which accelerated the falling off of some corrosion products in the coating. In addition, the corrosion products gradually desquamated with the increase of the immersed time in seawater.However, the epoxy resin spraying on the coating surface prevented seawater entering the interior of the coating along the channel. Due to the penetration and diffusion of Cl^(-), the formation of corrosion products such as hydrated iron oxide was accelerated and parts of Fe^(2+)was taken away from the coating, which reduced the effective component content of functional materials in the coating. The reflectivity of samples was measured using bow method in the range of 2.0~18.0 GHz and the results showed that the reflection performance of the microwave absorbing coating decreased gradually with the increase of corrosion time, which eventually resulted the failure of the absorbing properties. For further analysis the evolution of the absorbent in coating, the electromagnetic parameters of the microwave absorbing coating before and after seawater corrosion were measured by the free space method. After 4 weeks of seawater corrosion, the real part of permittivity decreased from 140 to 42. In addition, the imaginary part of permittivity decreased from 35 to 3. Meanwhile, the real part of permeability decreased from 1.78 to 1.71 at 8.9 GHz and the imaginary part of permeability decreased from 2.8 to 1.8.The permeability and electromagnetic loss of the absorbing coating declined gradually with the increase of corrosion time. By analyzing the evolution of electromagnetic characteristics of absorbing coatings in hygrothermal and high chloride environments, the results could provide the theoretical basis for solving the problem of absorbing performance failure caused by absorbent deterioration in tropical marine environment.
作者
王雯
陈庆昌
李桂群
朱洪立
张成军
郭宇
Wang Wen;Chen Qingchang;Li Guiqun;Zhu Hongli;Zhang Chengjun;Guo Yu(Shandong Institute of Non-Metallic Materials,Jinan 250031,China;Bejing Special Vehicle Institute,Bejing 100072,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2023年第2期322-328,共7页
Chinese Journal of Rare Metals
基金
装备发展部预研领域基金项目(61402080204)资助。
关键词
吸波涂层
海水腐蚀
吸波性能
电磁参数
失效行为
microwave absorbing coating
seawater corrosion
absorption property
electromagnetic parameters
failure behavior
作者简介
王雯(1984-),女,山东济宁人,博士,研究员,研究方向:电磁波散射/辐射抑制材料,E-mail:wenwen1013@126.com;通信作者:郭宇,研究员,电话:15863195727,E-mail:guoyu528@163.com。
