共查询到19条相似文献,搜索用时 109 毫秒
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宽频带橡胶复合铁氧体电磁波吸波材料研究 总被引:12,自引:1,他引:11
采用M型六角晶系铁氧体材料与橡胶复合构成宽频带、薄型电磁波吸波材料。介绍了材料配方、制备工艺与特性。用弓形法,在2~18GHz频率范围研究了这种复合吸波材料的反射率特性,通过合理组合成复合吸波材料,当总厚度为20mm时,可在2~18GHz频率范围实现反射率≤-10dB。 相似文献
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采用柠檬酸盐溶胶凝胶法制得尖晶石型纳米钴镍锰锌铜铁氧体,通过原子吸收光谱仪测定元素组成,XRD、透射电镜、网络分析仪研究矿物组成并研究其颗粒形貌与吸波性能。试验表明:所得产物为尖晶石立方晶系铁氧体;其中铁元素易于被钴取代,形成CoFe2O4;而Mn、Zn、Cu、Ni趋向于互相掺杂形成固溶铁氧体。铁氧体的平均粒径为50nm。采用网络分析仪研究了5~7GHz,9~11GHz,15~18GHz内铁氧体的吸波性能:尖晶石型立方晶系纳米铁氧体具有良好的微波吸收性能;适量提高锰、锌等掺杂元素含量,有助于提高材料的吸波性能。 相似文献
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(MnZnCo)2—W和(MnZnCo)2—Y型复合铁氧体材料吸收微波特性的研究与 … 总被引:13,自引:2,他引:11
研制了六角晶系(MnZnCo)3-W和(MnZnCo)2-Y平面昨合铁氧体材料,测试了它们的有关电磁特性及吸收微波性能的参量。在X波范围内发现有3个吸收峰,讨论分析了其相关机理。实验比较表明,W型比Y型更具备从优平面材料,但作为吸收微波涂层材料,六有晶系平面型铁氧体又大大优于立方晶系的铁砂。 相似文献
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采用柠檬酸盐溶胶-凝胶法在碳化硅表面形成钡铁氧体薄膜.XRD表明生成的铁氧体为六角磁铅型晶体BaFe12O19.测定了材料在0.1~6.0 GHz内的介电常数与磁导率.与单纯钡铁氧体比较,碳化硅表面沉积钡铁氧体薄层后复合相吸波频段宽化,吸波能力增强. 相似文献
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稀土元素对W型钡铁氧体微波吸收特性的作用 总被引:1,自引:0,他引:1
采用化学共沉淀法制备W型钡铁氧体,研究稀土元素Dy、Nd、Pr掺杂对铁氧体微波特性的作用.发现:稀土元素的掺入能有效调整铁氧体的微波电磁参数,使自然共振频率向高频移动,并明显提高试样的高频弛豫特征,同时减小复介电常数,以利于阻抗匹配.在一定范围内增大Dy的掺杂量x,有利于进一步获得低介电损耗和高磁损耗,用数值计算模拟方法得到x=0.05时匹配厚度下铁氧体在2~18GHz范围的反射率曲线:吸收峰值达-52.34dB,吸收率小于-10dB的带宽7.9GHz,结果表明稀土Dy掺杂有利于制备轻、薄铁氧体吸波材料. 相似文献
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Yuan PuHua Zou Jie-Xin WangJing Zhai Neil R. Foster Jian-Feng Chen 《Materials Letters》2011,65(14):2213-2215
Novel one-dimensional structured SrZnCoFe16O27 hexagonal ferrites were successfully prepared by using the nature pine-wood template assisted chemical solution method. The diameters of the w-type hexagonal ferrite nano-rods obtained were in the range of 500 ± 50 nm and the length attained was 5-6 μm. The one-dimensional structured SrZnCoFe16O27 hexagonal ferrite exhibited magnetop lumbite structure and presented hard magnetic properties. The magnetization value of the rod-like ferrites was much higher than that of the bulk hexagonal ferrites. The reasonable explanation of the improvement in the magnetization value was the shape effect. To our knowledge, only a few papers have reported the successful preparation of 1D structured Ba/Sr hexagonal ferrite and this novel SrZnCoFe16O27 hexagonal ferrite can be potentially applied in magnetic material industries. 相似文献
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SiC(N)/LAS吸波材料吸波性能研究 总被引:6,自引:2,他引:6
研究了由SiC(N)纳米吸收剂制备的SiC(N)/LAS吸波材料的介电性能,对影响介电性能的吸收剂的含量、吸波材料烧结温度和碳界面层等因素进行了较为全面的研究。结果表明,在1080℃以下烧结温度对陶瓷致密度的影响较大而对陶瓷介电常数的影响较小;在1080℃以上烧结温度对烧结致密度的影响较小,对陶瓷介电常数的影响较大,吸波材料介电常数的实测值与计算值之间存在很大的差异,这种差异是吸波材料制备过程中纳米级的SiC(N)促进了碳界面层形成,导致了在较高温度烧结时吸波材料介电常数对温度的敏感性,使吸波材料介电常数的实测值与计算值之间出现了很大的差异,形成的碳界面层复介电常数的虚部较高,使吸波材料对电磁波的损耗进一步升高,从而使吸波材料的吸波性能得到增强。 相似文献
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The aim of this study was to investigate the effects of nano hexagonal boron nitride(hBN) particles on the friction and wear properties of AISI 4140 steel material when the hBN particles are used as an oil additive. Nano hexagonal boron nitride powders, which were produced using a special process, were dispersed in engine oil (SAE10 W) to enhance lubrication. The amount of nano hexagonal boron nitride in the engine oil was varied from 0 to 10% by volume, and four different lubricant samples were prepared. Wear tests were conducted using ball-on-disc geometry. The worn surfaces of substrates were analyzed using scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDS). The experiments showed that the nano hexagonal boron nitride particles that were used as an oil additive affected the friction and wear behavior. A 14.4% improvement in the friction coefficient and a 65% decrease in the wear rate were achieved through the use of the nano hBN as an oil additive. 相似文献
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Soft magnetic material has been produced in which flaky thin amorphous metal particles, about 2 μm thick, are aligned in polymer in the direction perpendicular to electromagnetic wave propagation. This material yields a permeability two to three times higher than the spinel-type ferrite system in the quasi-microwave band. We have designed a thin wave absorber composed of the present material by introducing a low-permittivity area such as a free space into the present metal-containing material. This decreases the average permittivity, striking a balance between complex permeability and permittivity values, and thus reducing the reflection coefficient of the absorber. A thin (about 3-mm thick) wave absorber with a reflection loss of over 30 dB in the quasi-microwave band was successfully obtained when the free space region was 5% of the total volume 相似文献
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采用普通陶瓷工艺制备了Gd掺杂的Co2Z型平面六角铁氧体3(Ba0.5Sr0.5O).2CoO.0.05Gd2O3.10.8Fe2O3,对其微结构和高频性能进行了研究。结果表明,少量掺杂Gd的Co2Z型铁氧体仍具有单相的Z型平面六角结构,其磁导率实部μ′明显提高,可达到13,而截止频率仍大于1GHz,具有较好的高频性能。随着烧结温度的提高,材料的磁导率实部μ′增大,但截止频率下降。少量Gd的掺杂对Co2Z型铁氧体的复介电常数值没有明显影响,但材料的铁电共振峰向高频区移动。 相似文献