Improvement on electromagnetic absorbing performance of Al18B4O33w/Co composite particles through heat treatment

A significant improvement in electromagnetic wave absorbing performance is achieved in an Al18B4O33w/Co based coating through the heat treatment of Al18B4O33w/Co particles. The electromagnetic properties of the Al18B4O33w/Co composite particles clearly increase after heat treatment. A maximal reflection loss of 78.3 dB and a high-efficiency absorption band of 4 GHz was obtained with an improved coating about 2 mm thick. Additionally, the absorption band was found to be able to cover the 7–18 GHz band by adjusting the coating thickness.