In this work, an epoxy-based microwave absorbing coating (MAC) containing carbon nanotube (CNT), silicon carbide (SiC), and carbonyl iron (CI) particles was prepared. In order to achieve some optimum key properties such as high and broadband microwave absorbing properties, low density, and relatively low cost, a gradient structure and alternating multilayer structure are used simultaneously. The effect of a single layer containing one type of filler, single layer containing several types of fillers, and multilayer structures on mentioned key parameters are investigated. The electromagnetic parameters and the reflection loss (RL) versus frequency of samples were tested by network analyzer in the range of 2–18 GHz using the transmission/reflection method. As a final result, the multilayer MACs included nine layers in which each of the layers contained one type of the fillers (CNT, CI, and SiC) and three neat resin interlayers 2 mm in total thickness compared to other samples and provided a maximum return loss value of 17.6 dB at 08.50 GHz and an absorption bandwidth (RL < − 5 dB) of 16 GHz (2–18 GHz) with a density of 1.61 g/cm³. So, it is simply possible to obtain an efficient MAC due to suitable microwave absorbing filler distribution in multilayer coatings for any respective application.

中文翻译：

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包含碳纳米管（CNT），碳化硅（SiC）和羰基铁（CI）颗粒的环氧树脂基多层涂层：作为有效的微波吸收材料

在这项工作中，制备了包含碳纳米管（CNT），碳化硅（SiC）和羰基铁（CI）颗粒的环氧基微波吸收涂层（MAC）。为了获得一些最佳的关键特性，例如高和宽带微波吸收特性，低密度和相对低成本，同时使用梯度结构和交替的多层结构。研究了包含一种填料的单层，包含几种填料的单层和多层结构对上述关键参数的影响。使用传输/反射方法，通过网络分析仪在2–18 GHz范围内测试了电磁参数和反射损耗（RL）与频率的关系。最后的结果³。因此，由于在任何相应应用的多层涂层中都有合适的微波吸收填料分布，因此很可能获得有效的MAC。