共查询到19条相似文献,搜索用时 146 毫秒
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聚磷腈材料及其在固体火箭发动机绝热层中的应用探讨 总被引:1,自引:0,他引:1
聚磷腈是一种具有少烟或无烟、耐油及低烧蚀率优点的无机聚合物材料,适用于低特征信号固体火箭发动机绝热层。主要对其结构、特性、合成方法及其在绝热层中的应用进行了概述,并对其未来的发展作了展望。 相似文献
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低特征信号固体推进剂合成方法探讨 总被引:3,自引:0,他引:3
介绍了特征信号产生的原因及降低推进剂特征信号的途径,解决了因降低推进剂特征信号而造成推进剂能量低的矛盾,用实例说明合成低特征信号推进剂的方法,提出了今后在研制低特征信号推进剂方面应注意的事项。 相似文献
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为研制新型少烟、低密度、耐烧蚀材料,将笼形八乙烯基硅倍半氧烷(OVP)与三元乙丙橡胶(EPDM)通过双辊混炼机制成无机-有机纳米杂化烧蚀材料,考察了材料的力学、烧蚀、低特征信号和密度等主要性能。结果表明,用OVP取代部分聚磷酸铵(APP)后烧蚀材料的线烧蚀率显著降低,从0.077mm/s降低到0.056mm/s,同时烟雾和密度也有所降低。 相似文献
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为研制新型少烟、低密度、耐烧蚀材料,将笼形八乙烯基硅倍半氧烷(OVP)与三元乙丙橡胶(EPDM)通过双辊混炼机制成无机-有机纳米杂化烧蚀材料,考察了材料的力学、烧蚀、低特征信号和密度等主要性能.结果表明,用OVP取代部分聚磷酸铵(APP)后烧蚀材料的线烧蚀率显著降低,从0.077 mm/s降低到0.056 m m/s,同时烟雾和密度也有所降低. 相似文献
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美国福特汽车公司的特殊车辆研究部正在进行一项有关塑料发动机的研制工作。这种90%的部件由纤维增强塑料制成的发动机,将安装在福特公司的Mustang牌小型轿车上。这种树脂制品主要含分别由玻璃纤维或石墨纤维增强的环氧或聚酰亚胺树脂。发动机内仅有的金属部件是四个排气阀和螺栓,以及控制轴、凸轮衬套和曲柄轴。该发动机纤维增强材料的重量为40磅,树脂的重量为60磅,金属材料的重量为68磅,总重量比普通同型发动机轻200磅,且具有更经久耐用,噪音低30%和能节约燃油等优特点。(叶春葆摘自《Chemical Week》2.26,1998)新纤维增强塑料… 相似文献
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降低推进剂特征信号的新材料——支化GAP 总被引:2,自引:0,他引:2
综述了国外在研制低特征信号推进剂含能粘结剂-支化GAP方面所取得的最新进展,介绍了支化GAP的合成和物化性能以及在固体推进剂中的应用情况。 相似文献
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Recent demand for high‐frequency and high‐speed signal transmission over GHz is driving the printed circuit board (PCB) industry towards a more advanced material‐based era. To meet this market demand, liquid crystal polymer (LCP) has been suggested for its predominant material characteristics, such as high temperature resistance, low moisture absorption and excellent dimensional stability. However, former experimental and theoretical studies on the fabrication technology for processing the LCP PCB at different treatment conditions are lacking. This article thus evaluates the recent development of LCP PCB process technology. Different process approaches involving in lamination, drilling, desmearing, and metallization are proposed and compared, and associated reliability testing is addressed. Experimental results are shown to demonstrate the efficacy of the proposed approach for developing the process technology of LCP PCB. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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Nina Balke Doru C. Lupascu Torsten Granzow Jürgen Rödel 《Journal of the American Ceramic Society》2007,90(4):1081-1087
In actuator applications, a degradation of the ferroelectric material occurs both under unipolar cycling as well as DC loads. The developing material state is characterized by measurements of large and small signal unipolar as well as bipolar hysteresis loops. While the unipolar loops indicate a small decrease in strain and polarization amplitudes, the bipolar loops unveil the development of an offset field, an offset polarization, and an asymmetry in the hysteresis of strain and dielectric constant. A mechanism for unipolar fatigue is suggested to explain the observed changes in material properties with cyclic loading. 相似文献
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Zahra Negahdari Monika Willert-Porada Florian Scherm 《Journal of the European Ceramic Society》2010,30(15):3103-3109
Lanthanum hexaaluminate has the potential to be applied in thermal barrier coatings due to its relative low thermal conductivity and low sinterability at temperatures higher than 1100 °C. One of the main problems in developing this material as a thermal barrier coating is difficulty in controlling the microstructure in order to combine the low thermal conductivity with high structural reliability.The idea behind this study was to take advantage simultaneously of the low thermal conductivity of lanthanum hexaaluminate and of the high mechanical properties of alumina by developing alumina-rich and lanthanum hexaaluminate-rich alumina/lanthanum hexaaluminate ceramic composites. The thermal properties of the alumina/hexaaluminate ceramic composites were compared as a function of temperature and lanthanum hexaaluminate content (20–80 vol.%). The results showed that the alumina/lanthanum hexaaluminate ceramic composites have sufficient low thermal conductivity to be used in thermal barrier coatings. 相似文献
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纳米钛酸镁陶瓷粉体的制备研究进展 总被引:2,自引:0,他引:2
钛酸镁粉体是一种非常重要的微波介质陶瓷材料,具有很高的品质因素(Q值)和较低的介电常数,得到了广泛应用。介绍了纳米钛酸镁粉体的主要制备技术,包括沉淀法、溶胶-凝胶法、机械力化学法等,分析了各种制备方法的发展现状、优势及不足。最后,指出了纳米钛酸镁粉体的发展方向。 相似文献
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聚氨酯塑胶跑道的发展趋势浅析 总被引:10,自引:3,他引:7
简要介绍了聚氨酯塑胶跑道的发展趋势,并介绍了表面压花卷材型塑胶跑道、现场浇注压花型塑胶跑道、表面颗粒包胶喷洒型塑胶跑道、低成本双层塑胶跑道及特殊要求的铺装材料的结构及铺装工艺等。 相似文献
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包膜缓控释肥料用包膜材料的探讨 总被引:2,自引:0,他引:2
简要介绍关于目前国内外缓控释肥料的生产及包膜缓控释肥料生产用包膜材料的种类和特点;阐述开发利用缓效、长效肥料,特别是水溶性低的肥料为速溶、速效性肥料的缓控释包膜材料,采用“以肥包肥”缓控释技术的必要性及取得的成果. 相似文献