耐海洋腐蚀的双层稀土掺杂铁氧体/聚氨酯吸波复合材料  

Marine Corrosion-resistant Bilayer Rare Earth-doped Ferrite/Polyurethane Wave-absorbing Composites

作　　者：肖冬梅 程振宇 刘一杰 段吕桐 周金堂[1] XIAO Dongmei;CHENG Zhenyu;LIU Yijie;DUAN Lvtong;ZHOU Jintang(College of Materials Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 211100,China)

机构地区：[1]南京航空航天大学材料科学与技术学院,南京211100

出　　处：《表面技术》2024年第22期161-170,共10页Surface Technology

基　　金：国家重点研发项目(2021YFB3502500);国家自然科学基金(52172295)。

摘　　要：目的开发一种防腐性和吸波性能均良好的新型复合材料。方法制备了一种新型的双层吸波复合材料,其中匹配层使用30%(质量分数)稀土铁氧体粉的Ce-铁氧体/TPU复合材料,吸收层则使用70%(质量分数)稀土铁氧体粉的Ce-铁氧体/TPU复合材料。在制备过程中,首先将稀土铁氧体粉和TPU树脂按照一定的比例混合,并通过机械搅拌使其均匀分散。然后,将混合物填充在模具中,并进行高温热压处理,以实现复合材料的固化和成型。结果通过数值计算,发现双层吸收体的微波吸收性能比其组分有很大的提高。与此同时,在总厚度保持不变的条件下,充分利用30%~70%的层厚度比例进行调节以改善有效吸收带宽的情况,并基于RL(反射损耗)优化了厚度3.5 mm/1.5 mm的30%~70%双分子层。当频率为15.76 GHz时,最大RL峰为-26.4 dB,有效吸收带宽达12.32 GHz(5.68~18 GHz)。通过适当的阻抗匹配和多种损耗形式,可以显著提高30%~70%双层吸收体的微波吸收性能。结论将30%(质量分数)稀土铁氧体粉的Ce-铁氧体/TPU复合材料和70%(质量分数)稀土铁氧体粉的Ce-铁氧体/TPU复合材料组合形成双层后,其电磁性能明显上升,达到了良好的阻抗匹配。其中30%(质量分数)稀土铁氧体粉的Ce-铁氧体/TPU复合材料的耐腐蚀性能略高于70%(质量分数)稀土铁氧体粉的Ce-铁氧体/TPU复合材料的,将二者组合后,其防腐性能也有所提升,由此制得的双层材料的耐腐蚀性和吸波性能均得到了提升。Microwave absorbers are susceptible to strong corrosion in the marine environment,leading to significant limitations in their application.Therefore,the development of composites with stronger corrosion resistance and wave-absorbing properties is imminent.The work aims to prepare new double-layer wave-absorbing composites by Ce-ferrite/TPU composites with a 30%mass fraction of rare-earth ferrite powder as the matching layer and Ce-ferrite/TPU composites with a 70%mass fraction of rare-earth ferrite powder as the wave-absorbing layer.Among them,the preparation process of the single-layer composites is to keep the total mass of the rare-earth-doped ferrite powder and polyurethane unchanged at 12 g.The rare earth-doped ferrite powder with mass fractions of 30%and 70%was weighed,respectively,and a three-necked flask was erected.Firstly,the DMF solution was poured in and the stirring paddles were opened to raise the temperature to 80℃,and then the DMF solution was poured in the polyurethane(TPU),so that the DMF solution and the polyurethane(TPU),which had been previously heated to 80℃,were mixed in the stirring paddles.The DMF solution was fully dissolved under the stirring of the paddles for about two hours,after which the weighed rare earth-doped ferrite powder was poured in to fully react with TPU,and then the above reaction system was placed in a vacuum drying oven for the removal of bubbles and then put into the oven to dry the DMF solution,and a single-layer Ce-ferrite/TPU composite material could be obtained after the above operation.According to the experimental results,the composition of the double-layer material was determined.The RL value of 30%Ce-ferrite/TPU was not less than–10 dB,which indicated that the microwave absorption ability of 30%Ce-ferrite/TPU composites was poor,and then,according to the concept of impedance matching,the 30%Ce-ferrite/TPU with a lower reflectance was selected as the matching layer,which enabled more microwaves to enter the absorber.At the same time,at the frequency of 7.9

关 键 词：吸波 防腐蚀 多层结构 稀土掺杂铁氧体 复合材料 

分 类 号：TG174[金属学及工艺—金属表面处理] TB34[金属学及工艺—金属学]