To develop electromagnetic protection composites with integrated structure -function properties, the three-dimension (3D) braided nickel plated carbon fiber/epoxy resin (Ni-CF3D/EP) composites were prepared based on 3...To develop electromagnetic protection composites with integrated structure -function properties, the three-dimension (3D) braided nickel plated carbon fiber/epoxy resin (Ni-CF3D/EP) composites were prepared based on 3D five-directional braiding, unitary nickel plating and mold compression shaping. The electromagnetic protection properties of Ni-CF3D/EP composites including shielding effective- ness (SE) and reflection loss against plane electromagnetic wave, shielding properties against electromagnetic pulse (EMP) were investigated. The test results show that the novel composites have good electromagnetic protection properties in a wide frequency range of 14 kHz～18 GHz with SE of 42 dB～95 dB, the absorption bandwidth of –5 dB in 2 GHz～18 GHz can reach 10 GHz and the pulse peak SE against EMP is 43.7 dB which can reduce the electromagnetic energy greatly. Meanwhile, the mechanic properties were also investi- gated and the results indicate that the Ni-CF3D/EP composites can replace metal materials for loading-bearing structural applications because of their excellent mechanic properties.展开更多
采用单一助剂硅烷偶联剂KH-560、表面活性剂硬脂酸钙和复合助剂（KH-560＋硬脂酸钙）分别通过高能球磨制备片状羰基铁粉吸波材料的样品,系统地分析研究样品的微观形貌、物相、电磁参数,并通过电磁场传输线理论模拟计算吸波涂层反射损耗...采用单一助剂硅烷偶联剂KH-560、表面活性剂硬脂酸钙和复合助剂（KH-560＋硬脂酸钙）分别通过高能球磨制备片状羰基铁粉吸波材料的样品,系统地分析研究样品的微观形貌、物相、电磁参数,并通过电磁场传输线理论模拟计算吸波涂层反射损耗。结果表明：与单一助剂样品相比,复合助剂样品团聚现象明显减少,形成了平整、光滑的片状结构;模拟计算在2 mm厚度下,反射损耗小于–10 d B,复合助剂样品带宽达到1 GHz（1.4～2.4 GHz）,且在2 GHz处的反射损耗峰值也达到–15 d B,均优于单一助剂样品。复合助剂的使用可以增强偶联剂和表面活性剂在片状羰基铁粉颗粒的表面包覆效果,达到更好的介电调控目的,提高低频吸波性能。展开更多
采用真空悬浮熔炼和高能球磨工艺制备Mn-Al基合金粉体,使用XRD、SEM和网络矢量分析仪研究Ce含量对MnAl粉体组织结构和微波吸收特性的影响。结果表明:随着加入Ce含量的增加,AlMnCe粉体Al_8Mn_4Ce相随着增多,同时AlMnCe合金粉体复数介电...采用真空悬浮熔炼和高能球磨工艺制备Mn-Al基合金粉体,使用XRD、SEM和网络矢量分析仪研究Ce含量对MnAl粉体组织结构和微波吸收特性的影响。结果表明:随着加入Ce含量的增加,AlMnCe粉体Al_8Mn_4Ce相随着增多,同时AlMnCe合金粉体复数介电常数虚部ε″和复数磁导率虚部μ″的共振峰频率及反射损耗峰频率均向低频移动;当涂层厚度为1.8 mm时,Al_8Mn_4Ce粉体的反射率最小值达到约–26.9 d B。展开更多
基金Project supported by Equipment Pre-research Foundation of China (9140A31030110JB3403)
文摘To develop electromagnetic protection composites with integrated structure -function properties, the three-dimension (3D) braided nickel plated carbon fiber/epoxy resin (Ni-CF3D/EP) composites were prepared based on 3D five-directional braiding, unitary nickel plating and mold compression shaping. The electromagnetic protection properties of Ni-CF3D/EP composites including shielding effective- ness (SE) and reflection loss against plane electromagnetic wave, shielding properties against electromagnetic pulse (EMP) were investigated. The test results show that the novel composites have good electromagnetic protection properties in a wide frequency range of 14 kHz～18 GHz with SE of 42 dB～95 dB, the absorption bandwidth of –5 dB in 2 GHz～18 GHz can reach 10 GHz and the pulse peak SE against EMP is 43.7 dB which can reduce the electromagnetic energy greatly. Meanwhile, the mechanic properties were also investi- gated and the results indicate that the Ni-CF3D/EP composites can replace metal materials for loading-bearing structural applications because of their excellent mechanic properties.
文摘采用单一助剂硅烷偶联剂KH-560、表面活性剂硬脂酸钙和复合助剂（KH-560＋硬脂酸钙）分别通过高能球磨制备片状羰基铁粉吸波材料的样品,系统地分析研究样品的微观形貌、物相、电磁参数,并通过电磁场传输线理论模拟计算吸波涂层反射损耗。结果表明：与单一助剂样品相比,复合助剂样品团聚现象明显减少,形成了平整、光滑的片状结构;模拟计算在2 mm厚度下,反射损耗小于–10 d B,复合助剂样品带宽达到1 GHz（1.4～2.4 GHz）,且在2 GHz处的反射损耗峰值也达到–15 d B,均优于单一助剂样品。复合助剂的使用可以增强偶联剂和表面活性剂在片状羰基铁粉颗粒的表面包覆效果,达到更好的介电调控目的,提高低频吸波性能。
文摘采用真空悬浮熔炼和高能球磨工艺制备Mn-Al基合金粉体,使用XRD、SEM和网络矢量分析仪研究Ce含量对MnAl粉体组织结构和微波吸收特性的影响。结果表明:随着加入Ce含量的增加,AlMnCe粉体Al_8Mn_4Ce相随着增多,同时AlMnCe合金粉体复数介电常数虚部ε″和复数磁导率虚部μ″的共振峰频率及反射损耗峰频率均向低频移动;当涂层厚度为1.8 mm时,Al_8Mn_4Ce粉体的反射率最小值达到约–26.9 d B。
文摘针对目前水泥基吸波材料带宽窄、吸收率低、而且制备成本高的问题,选用铁尾矿与钢渣固废资源为胶凝填充材料,利用钢纤维作为吸波剂制得电磁波吸收复合材料。采用矢量网络分析仪测定复合材料在0.1~5 GHz范围内的相对复介电常数与复磁导率,计算得到其电磁波损耗系数与反射率,并制备不同厚度样品分析了复合材料的电磁波吸收机理。研究表明:铁尾矿与钢渣中的磁性矿物相组分能显著提升材料的电导能力,影响电磁参数,提升介电损耗与磁损耗能力;增加钢纤维吸波剂的使用量能够降低与之匹配复合材料的最小厚度,当铁尾矿、钢渣掺量分别为10%、30%,钢纤维体积比为0.5%时,制备出的15 mm厚度复合吸波材料最小反射率达到-46.863 d B,有效带宽占比18.8%。
