NiZn铁氧体包覆FeSiAl合金复合材料及其微波电磁性能

NiZn-ferrite-coated FeSiAl alloy composite and its microwave electromagnetic properties

通过熔炼法制备FeSiAl合金块体,破碎后利用球磨机进行扁平化处理,得到扁平化的FeSiAl合金粉体,采用化学共沉淀法在其表面生成NiZn氢氧化物。然后通过反应釜水热法在FeSiAl合金粉末表面生成NiZn铁氧体,最后在真空中进行500℃热处理使铁氧体生长更加完全。研究了NiZn铁氧体粉体包覆FeSiAl合金复合材料的电磁性能。测试和仿真表明,相对于FeSiAl合金粉体复合材料介电常数下降明显,而复磁导率变化不大,作为吸波材料提高了阻抗匹配特性。因而,在FeSiAl合金粉体上包覆NiZn铁氧体,可显著改善FeSiA合金粉体的吸波性能。

FeSiAl bulk alloys were prepared by melt and flake FeSiAl alloy powders were prepared by subsequently cracking and milling, then NiZn hydroxide was synthesized on the surface of FeSiAI alloy powders by chemical co-precipitation method. NiZn hydroxide was transformed to NiZn spinel-ferrite by hydrothermal method, then NiZn spinel-ferrite grows more fully by 500~C heat treatment in vacuum. Electromagnetic properties of the composite materials were investigated. The test and simulation results showed that, the dielectric constant of the composite materials decreases obviously and the complex permeability does not change obviously compared to that of FeSiAl alloy, and consequently the impedance matching was improved as absorbing material. Thus, absorptivity of FeSiAl alloy powders coated with NiZn ferrite is greatly improved.