Preparation and evaluation of composite electromagnetic wave absorbers made of fine aluminum particles dispersed in polystyrene medium
Preparation and evaluation of composite electromagnetic wave absorbers made of fine aluminum particles dispersed in polystyrene medium
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聚苯乙烯介质中细铝颗粒复合电磁波吸收体的制备及性能评价
DOI：
10.2529/piers071220014249
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
S. Yoshikado
中科院分区：
文献类型：
--
作者：
Y. Wada;N. Asano;K. Sakai;S. Yoshikado
我们开发了由分散在聚苯乙烯介质中的金属铝颗粒制成的复合电磁波吸收剂，并评估了它们的性能，以实现在GHz区域具有良好吸收性能的金属背衬单层电磁波吸收剂。所有样品的磁化强度和表面涡流引起的磁损耗均随铝颗粒体积比的增大而增大。磁化强度几乎与频率无关，但所有样品的磁损耗均随频率的增加而减小。这些结果与定性理论预测一致。在几个GHz的频率范围内吸收电磁波，随着频率的增加而减少。因此，由于吸收需要小于1的值，所以当开发电磁波吸收材料时，磁矩出现的条件是一个重要因素。当材料中铝克莱斯的比例增加时，推测磁矩增加，并且“0”变得小于1。然而，如果铝颗粒彼此接触，则颗粒的总表面电流减小，因为颗粒的总表面积减小。结果，由于涡电流引起的损耗“00”将很小。此外，由于电磁波吸收材料的导电性在铝颗粒接触时增加，并且电磁波的反射系数增加，因此波难以穿过材料内部。最终，波不能被有效地吸收，因为焦耳损耗变小。因此，在本研究中，制造了由涂覆有聚苯乙烯树脂的铝颗粒制成的电磁波吸收材料，该聚苯乙烯树脂是绝缘体并确保铝颗粒彼此不接触，并对其特性进行了评价。
We developed composite electromagnetic wave absorbers made of flne aluminum particles dispersed in a polystyrene medium and evaluated their properties in order to realize metal-backed single-layer electromagnetic wave absorbers with a good absorption property in the GHz region. Both the magnetization and the magnetic loss caused by the eddy current ∞owing on the surface of the aluminum particles increased proportionally to the volume mixture ratio of the aluminum particles for all samples. The magnetization was almost independent of frequency but the magnetic loss decreased with increasing frequency for all samples. These results were in agreement with qualitative theoretical predictions. mines the absorption of electromagnetic waves over a frequency range of several GHz, decreases with increasing frequency. Therefore, since the values of " 0 smaller than 1 is required for ab- sorption, the conditions under which the magnetic moment appears is an important factor when electromagnetic-wave-absorbent materials are developed. When the proportion of aluminum parti- cles in the material increases, it is speculated that the magnetic moment increases and " 0 becomes smaller than 1. However, if aluminum particles are in contact with each other, the total surface current of the particles decreases because the total surface area of the particles decreases. As a result, the loss " 00 due to the eddy current will be small. Furthermore, because the conductivity of the electromagnetic-wave-absorbent materials increases upon the aluminum particles coming in contact and the re∞ection coe-cient of the electromagnetic wave increases, it is di-cult for the wave to pass through the materials inside. Eventually, the wave cannot be efiectively absorbed, because the Joule loss becomes small. Therefore, in this study, electromagnetic-wave-absorbent materials made of aluminum particles coated with polystyrene resin, which is an insulator and ensures that the aluminum particles do not come in contact with each other, were fabricated and their characteristics were evaluated.