片状还原铁粉的制备及电磁性能研究

Preparation and electromagnetic properties of flaky reduced iron powders

以小于250目（58μm）的还原铁粉为原料,直径3 mm的ZrO2球为磨球,采用湿法球磨制得片状还原铁粉;利用扫描电子显微镜、X射线衍射仪和矢量网络分析仪分别表征了球磨前后还原铁粉的形貌、物相结构和其在2-18 GHz的电磁参数,并运用传输线理论模拟了其反射率（RL）。结果表明：球磨后的还原铁粉呈片状,片厚度为100-200 nm;与球磨前样品相比,球磨后样品的ε′和μ′增大约2倍,ε″增大7-10倍,μ″增大2-4倍;相应2 mm厚的涂层在8.12 GHz有最小RL=–60 d B,RL〈–10 d B的带宽为9.48 GHz（5.12-14.60 GHz）。

Flaky reduced iron powders were prepared by wet ball milling method using reduced iron powders as raw material（less than 250 mesh, 58 μm） and Zr O2 balls as grinding balls（3 mm in diameter）. The morphologies, phases and electromagnetic parameters（2–18 GHz） of reduced iron powders before and after ball milling were characterized by scanning electron microscopy, X-ray diffraction and vector network analyzer, and their reflectivity（RL） were calculated using transmission line theory. The results show that the reduced iron powders after ball milling are flaky with thickness of100–200 nm. The ε′ and μ′ of reduced iron powders are increased by twice after ball milling, and the ε″ and μ″ are increased by 7–10 and 2–4 times, respectively. The corresponding coating with a thickness of 2 mm obtained a minimum RL of –60d B at 8.12 GHz and a bandwidth of 9.48 GHz（5.12–14.60 GHz） while RL〈–10 d B.