(SiC)p表面修饰及吸波性能研究

目的提高(SiC)P的吸波性能。方法采用低成本、环保型的化学镀镍方法对(SiC)P表面进行修饰,设计了氧化、亲水、敏化、活化系列增强前处理工艺,确定了(SiC)P表面修饰的最佳工艺流程。用SEM、EDS、XRD等分别表征了修饰前后(SiC)P形貌、成分、物相的改变,采用波导法测定了修饰后碳化硅复合粉体的介电性能,并以其为吸波剂在铝板上制备了吸波材料。结果修饰后,获得了镀层连续、无光滑(SiC)P裸露的较高质量的碳化硅复合粉体(简写为(Ni/SiC)P)。(Ni/SiC)P较原粉(SiC)P,其形貌、组成、结构发生了明显改变,且介电常数、介电损耗、吸波性能明显增强,其中,介电常数的实部增强约为22%,虚部增强约为20%。涂覆1层(Ni/SiC)P涂料,在17.12 GHz时,RL=−15.47 dB,大于涂敷2层原粉(SiC)P涂料的吸收效果。涂覆2层(Ni/SiC)P涂料,在16.11 GHz时,RL=−23.51 dB。结论采用低成本、环保型方法实现了(SiC)P表面高质量修饰,修饰后,复合颗粒(Ni/SiC)P的介电性能及吸波性能均明显提高。

Surface Modification and Microwave Absorption Properties of (SiC)P

The work aims to improve the microwave absorption performance of (SiC)P. The surface of (SiC)P was modified by low-cost and eco-friendly electroless nickel plating method. The oxidized, hydrophilic, sensitized and activated series enhanced pretreatment process was designed to determine the best surface modification flow of (SiC)P. The morphology, composition and phase of (SiC)P before and after plating were characterized by SEM, EDS and XRD. The dielectric properties of the modified (SiC)P powder were measured by waveguide method. On an aluminum substrate, the obtained sample was made into the wave absorbing material. A high-quality modified silicon carbide composite powder with a continuous coating and no smooth (SiC)P bareness was obtained ((Ni/SiC)P). After modification, the morphology, composition and structure of (SiC)P were significantly changed, and the dielectric constant, dielectric loss and absorbing properties had an obvious improvement. Among them, the real permittivity increased by 22% and the imaginary permittivity increased by 20%. When one-layer (Ni/SiC)P was coated on the sample, the reflection loss (RL) reached -15.47 dB at 17.12 GHz, which was more than absorption performance of two-layer (SiC)P coating. After two-layer (Ni/SiC)P was coated, the RL of absorber reached -23.51 dB at 16.11 GHz. High quality modification of (SiC)P surface can be achieved by low cost and environmental protection method. After modification, the dielectric properties and wave absorption performance of (Ni/SiC)P particles are significantly improved.