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利用真空热加工技术制备了具有不同结构的高孔率泡沫钛,研究了它们在无线电波频率范围的电磁屏蔽效能。这些泡沫钛样品的孔隙尺寸在毫米级,孔率都在85%以上。工作结果表明,这些泡沫钛具有明显的电磁屏蔽效能,低频段的屏蔽效果良好。在整个测试频率范围内,屏蔽效果大致随频率的增大而降低,超过某一频率值后,屏蔽效能曲线出现一个具有起伏性的平台。该平台区跨幅较大,包含数个吉赫兹的范围。分析还表明,本泡沫钛样品在低频区的电磁屏蔽机制主要是反射损耗,在频率较高的区间主要是吸收损耗。因此,上述平台出现在整个屏蔽效能曲线的低值区。
High-porosity titanium foams with different structures were prepared by vacuum thermal processing, and their electromagnetic shielding effectiveness in the radio frequency range was studied. The pore size of these foamed titanium samples is on the order of millimeters and the porosity is above 85%. The working results show that these foamed titanium have obvious electromagnetic shielding effectiveness and good shielding effect in low frequency range. In the entire test frequency range, the shielding effect generally decreases with the increase of the frequency. After exceeding a certain frequency value, the shielding efficiency curve shows a platform with undulations. The platform area spans a large area containing several gigahertz. The analysis also shows that the electromagnetic shielding mechanism of the titanium foam sample in the low frequency region is mainly the reflection loss and the absorption frequency loss in the high frequency region. Therefore, the above platform appears in the low area of the entire shield effectiveness curve.