用于吸波材料的铁磁性/碳材料复合物

Ferromagnetic Carbon-based Composites for Wave Absorbing Materials

铁磁性材料具有良好的磁导特性、较大的磁损耗角正切以及多样的耗散电磁波能量形式,通常是雷达吸波剂的优先选择或重要组成部分;比重大、力学特性及耐候性差等不足大大限制了铁磁性材料作为吸波剂材料的应用。碳材料由于具有良好的介电、简单的复合、特殊的微观结构、较低的比重及稳定的化学特性,通常也是吸波剂的常用选择;但低频吸收差、有效频带窄是碳类吸波材料的短板。铁磁性材料与碳类材料进行复合,制备铁磁性碳基复合物不仅可以同时获得优异的介电损耗与磁损耗性能,又可以兼顾材料的机械特性与耐环境特性,解决易团聚、易脱落、易老化等问题,还可以显著降低合成材料的比重,在吸波领域有着广阔的应用前景。在收集并总结了近年来国内外铁磁性碳基复合材料研究进展的基础上,从材料电磁损耗机理、合成工艺等方面梳理了铁氧体碳基复合材料、羰基铁碳基复合材料和铝硅铁碳基复合材料的吸波应用进展,指出"组合化、结构化、微细化、功能智能化"是未来吸波材料的发展方向。

Accounting the higher permeability,larger magnetic loss tangent and diverse methods of energy dissipation of the electromagnetic wave,ferromagnetic materials are usually be the preferred choice that used for radar wave absorbing.Nevertheless,the application of ferromagnetic materials that for wave absorbing field was limited greatly due to its higher mass ratio,poor mecha-nical properties and weathering resistance.Performances of excellent dielectric properties,good composite properties,special microstructure,low mass ratio,strong chemical stability,convenient use and simple maintenance,carbon based materials are also be the preferred selection that used for electromagnetic waves(EMW)absorbing.Similar to ferromagnetic materials,carbon based material used for EMW absorbing also have some defections,such as poor rate of absorption in low frequency,narrow band,etc.Abundant preliminary studies shown that combination of ferromagnetic and carbon-based materials not only exhibits satisfied dielectric and magnetic loss performance,but also appears the characteristics of resistance to environmental and mechanical properties,and the problems of agglomeration,easy to fall off,aging and other issues also can be solved at the same time.It can be imaged that composites of ferromagnetic/carbon based will have a bright future in EMW absorbing field,because of the weight reduced significantly in the meanwhile.In this investigation,basic researches,for instance,the loss mechanisms,synthesis processes,over the past decades in the field of ferromagnetic/carbon based composite materials that used for EMW absorbing have been studied.Based on the analysis&comparisons of the status and progresses of ferromagnetic carbon-based composite materials,iron carbon composite materials and three aluminum ferrosilicon carbon composite materials,it can be pointed out that the direction of“the combination,structure,miniaturization and intelligent function”will be the future in area of EMW absorbing material development.