羰基铁粉吸波涂层的优化设计

Optimized design of the wave-absorbing coating made of carbonyl iron powders

采用机械研磨工艺制备了片状羰基铁粉，并以此制备了羰基铁粉复合材料。研究了研磨时间对羰基铁粉复合材料电磁性能的影响，并对羰基铁粉吸波涂层进行了优化设计。结果表明：当研磨时间小于12h时，随着研磨时间的增加，羰基铁粉复合材料的介电常数和磁导率逐渐增大。以研磨12h的羰基铁粉（厚0．7mm）为底层，原始羰基铁粉为表层（厚1．4mm）的双层结构吸波涂层性能最优，其反射损耗在3．12—18．00GHz频域范围内小于-8dB，在2～18GHz频域范围内为-9．8dB（平均值）。该双层结构涂层可用于微波低频段的宽频薄层吸波涂层的制备。

Flake-like carbonyl iron powders were prepared by mechanical milling, and then carbonyl iron powder composites were prepared. The effects of milling time on the electromagnetic properties of the composites were studied, and the composition of the wave-absorbing coating made of carbonyl iron powder was optimized. The results show that, when the milling time is below 12h, both the permittivity and permeability of the composites increase gradually with increasing milling time; The wave-absorbing coating, composed of a 0.7 mm-thick bottom layer made of 12 h-milled carbonyl iron powder and a 1.4 mm-thick top layer made of as-received carbonyl iron powder, exhibits the best performance; Its reflection loss is below -8 dB in the range of 3.12 GHz and 18.00 GHz, and is -9.8 dB （in average） in the range from 2 GHz to 18 GHz. The coating with double-layer structure can be used as the broadband low-frequency microwave-absorbing coating with a small thickness.