共查询到19条相似文献,搜索用时 140 毫秒
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高性能复合材料中使用的新型纤维材料 总被引:1,自引:0,他引:1
随着社会的发展,人们对复合材料要求高性能化,因而使用普通的纤维材料已经远远不能适应。例如高性能复合材料中使用的填充纤维材料要求具有更高的强度、优良的耐热性能及其它一些特殊性能。这类高性能复合材料使用的是比玻璃纤维强度更高的纤维材料,例如其强度的比弹性模数要求在4×108cm以上,比强度在4×106cm以上。现介绍几种国外在开发研制高性能复合材料中使用的新型纤维材料。1碳纤维(CF)1970年日本研制开发了聚丙烯腈系碳纤维(PAN-CF),其后经过技术改进相继制造出了高强度级(HT)、高模量级(HM)以及通… 相似文献
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An electromagnetically transparent, structurally robust and environmentally resistant enclosure of radar antenna for ground based systems to modern avionics in military aircraft and missiles is called as radome. Radome materials are classified based on: (i) type of function - surface-based or flight-mode and (ii) speed of operation - subsonic, supersonic to hypersonic. The desired properties of these materials are low dielectric constant and low loss factor in addition to its capacity to withstand the high temperature of operation. Composite laminates of glass or aramid fibre reinforced polymeric resins are radome material candidates for applications in subsonic range. However, ceramics are the only viable option for military aerospace applications such as a fighter jet travelling at Mach 3 or an advanced hypersonic missile speeding up to Mach 5. This review outlines the hand-full of ceramic materials already in application as radome materials like high-purity-alumina, pyroceram, slip-cast-fused-silica, their processing technology, electromagnetic and mechanical properties, advantages and disadvantages with respect to advanced military vehicles. Use of silicon nitride based radome materials, that has exceptional mechanical strength and thermal stability up to 1400 °C is illustrated with respect to reaction bonded silicon nitride, hot pressed silicon nitride, silicon oxynitride, sialon and their composites. Design of new generation radome materials was conceptualized and discussed as applicable to silicon nitride and related ceramics, wherein incorporation of varied degree of porosity improves electromagnetic properties, simultaneously, maintaining the required mechanical strength. Multilayer and graded porosity and its influence on electromagnetic properties were briefly discussed. Si3N4 ceramics having controlled porosity leading to optimum electromagnetic and mechanical properties produced through systematic processing is proposed as the futuristic high temperature radome material for supersonic applications. 相似文献
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介绍大型地面雷达天线阵列防护罩所用的材料及其制造工艺。首次采用低压共固化工艺成功地制造了大尺寸的A型夹层结构雷达罩。结果表明,所选用的材料和工艺可行,雷达罩的整体性能和尺寸精度均满足性能指标要求。 相似文献
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飞机雷达罩用涂层材料工艺研究 总被引:1,自引:0,他引:1
介绍有机硅改性聚氨酯涂料的工艺及性能。该材料具有良好的耐候性、耐热性、耐雨蚀性和电传输效率;在涂刷工艺过程中通过控制工作粘度、温度、湿度等工艺参数,限定涂料消耗,选择溶剂、助剂等可以得到性能优良的飞机雷达罩保护涂层。 相似文献
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采用注射成型的方法制备出某弹载聚苯硫醚(PPS)天线罩。介绍了弹载天线罩对材料性能的要求、PPS的特性,以及PPS天线罩的注射成型过程、后处理过程,并比较了PPS天线罩与聚四氟乙烯(PTFE)天线罩的性能。结果表明,PPS天线罩的可制造性、尺寸稳定性等综合性能优于PTFE天线罩。 相似文献
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E. I. Suzdal’tsev D. V. Kharitonov A. A. Anashkina 《Refractories and Industrial Ceramics》2010,51(3):202-205
Radioparent materials that exist in the world, that may be used in the production of the radome of high-speed zenith guided
rocket fairings are analyzed. The main physicotechnical indices are provided for these materials and the future for their
application in radome production is indicated. 相似文献
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玻璃钢壳体电子性能预测技术研究 总被引:1,自引:0,他引:1
研究目的为通过人工神经网络方法预测玻璃钢天线罩的电子性能.建立具有非线性逼近能力的径向基函数(RBF)神经网络,根据试验得到的不同厚度玻璃钢平板,不同入射角的透波率数据,对神经网络进行训练.按照给定的玻璃钢天线罩内外表面数据计算入射角范围和罩壁厚度,并对玻璃钢壳体进行电子性能预测.计算结果与试验数据十分近似,表明该方法预测精度高,训练速度快,为玻璃钢电子性能设计和分析提供了一种实用有效的方法. 相似文献