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利用化学还原方法获取超细镍粉 ,将其制备成电磁防护涂料 ,分别测试 30～ 1 0 0 0 MHz频段范围的屏蔽效能和 2～ 1 8GHz频段范围的吸波性能。结果显示 :在测试范围内 ,含量为80 %的超细镍粉涂料屏蔽性能为 - 2 0～ - 30 d B之间 ,含量为 85 %的超细镍粉涂料吸波性能为 0～ - 9d B之间。将 2 0 0目镍粉与超细镍粉以 4∶ 1的比例混合制成含量为 75 %的涂料 ,测试结果表明 :在 1 0 k Hz～ 1 GHz范围内 ,屏蔽效能可提高到 - 30～ - 40 d B之间。扫描电镜分析结果显示 :混和镍粉在涂料中的分散性较好 ,粒度较大的镍粉能起到一定的填充作用 ,而超细粉又形成了一定的链状结构 ,增加了导电通路 ,可以使屏蔽效能增加
Ultrafine nickel powder was obtained by chemical reduction method and prepared into electromagnetic protective coating. The shielding effectiveness in the frequency range of 30-1 000 MHz and the absorbing performance in the frequency range of 2-18 GHz were respectively tested. The results show that the shielding performance of the ultrafine nickel powder coating with the content of 80% is between -20 ~ 30 d B and the absorbing performance of the ultrafine nickel powder coating with the content of 85% is 0 ~ 9d B between. The test results show that the shielding effectiveness can be increased to 30 in the range of 1 0 k Hz ~ 1 GHz by mixing 2 0 0 nickel powder and ultrafine nickel powder in the ratio of 4: 1. ~ - 40 d B between. Scanning electron microscopy analysis showed that the dispersibility of the mixed nickel powder in the coating is better, and the nickel powder with the larger particle size can play a certain role in filling, while the ultrafine powder forms a certain chain structure and increases the conductive path, Can increase the shielding effectiveness