Electromagnetic wave absorbing properties of Cr2AlB2 powders and the effect of high-temperature oxidation |
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| Authors: | Haiming Zhang Biao Zhao Huimin Xiang Fu-Zhi Dai Zhili Zhang Yanchun Zhou |
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| Affiliation: | 1. School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, China
Science and Technology on Advanced Functional Composite Laboratory, Aerospace Research Institute of Materials & Processing Technology, Beijing, China;2. Henan Key Laboratory of Aeronautical Materials and Application Technology, School of Material Science and Engineering, Zhengzhou University of Aeronautics, Zhengzhou, China;3. Science and Technology on Advanced Functional Composite Laboratory, Aerospace Research Institute of Materials & Processing Technology, Beijing, China;4. School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing, China |
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| Abstract: | The electromagnetic (EM) wave absorbing properties of Cr2AlB2 powders and those after high-temperature oxidation were investigated. Coupling of magnetic and dielectric loss enables Cr2AlB2 with good absorption properties. The minimum reflection loss (RL) value is −44.9 dB at 8.5 GHz with a thickness of 2.7 mm, and the optimized effective absorption bandwidth (EAB) is 4.4 GHz (13.0-17.4 GHz) with a thickness of 1.6 mm. After oxidation at 750, 900, and 1000°C for 2 h, the minimum RL values, respectively, are −23.9 dB (17.5 GHz, 1.5 mm), −41.4 dB (16.5 GHz, 1.5 mm), and −39.5 dB (8.0 GHz, 3.0 mm); and the corresponding EAB values, respectively, are 3.8 GHz (13.6-17.4 GHz, 1.7 mm), 4.1 GHz (13.5-17.6 GHz, 1.6 mm), and 4.4 GHz (13.0-17.4 GHz, 1.7 mm). With an absorber thickness of 1.5-4.0 mm, the EAB with a RL value of less than −10 dB can be tuned in a broad-frequency range 5.0-18.0 GHz, which basically covers C (4-8 GHz), X (8-12 GHz), and Ku (12-18 GHz) bands. These results demonstrate that Cr2AlB2, as a high-efficient and oxidation-resistant absorber, is a promising candidate for microwave absorption applications and can retain good EM wave absorbing properties after high-temperature oxidation. |
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| Keywords: | Cr2AlB2 dielectric and magnetic coupling layered ternary boride electromagnetic wave absorbing properties oxidation resistance |
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