• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>International Pyrotechnics Seminar >Physical properties of nano-scale WO_3 and their effect on performance of Al/WO_3 Metastable Intermolecular Compounds
【24h】

Physical properties of nano-scale WO_3 and their effect on performance of Al/WO_3 Metastable Intermolecular Compounds

机译：纳米级WO_3的物理性质及其对Al / WO_3亚稳态分子化合物的性能的影响

获取原文
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Tungsten tri-oxide is of interest as an oxidant for metals in metastable intermolecular composites (MICs),a reactive nano-scale powder useful for such applications as electric matches and gun primers.Smaller particles typically lead to fast reaction rates in this class of energetic material,and we have synthesized nano-scale WO_3 _ H2O using wet chemistry.Analysis by electron microscopy (EM) revealed approximately 1 OOnm x 7nm platelet morphology.Ammonium paratungstate was dissolved in acid and tungstic acid was precipitated by addition to distilled water and the resulting powder was dried and annealed.We observed annealing temperature to influence the performance metrics of peak pressure and burn rate when using MIC formulated with nano-scale aluminum as a fuel.Annealing conditions included ambient air atmosphere and temperatures ranging from 100 deg C to 600 deg C for durations of 1 hour to 15 hours.Peak pressures and peak pressurization rates decreased from a maximum of approximately 250 psi and 17 psi/microsecond,respectively,to 50 psi and 0.7 psi/microsecond with increasing annealing duration and temperature.Burning velocity decreased from 500 m/s to 180 m/s,also with increasing annealing duration and temperature.Thermogravimetric analysis (TGA) and x-ray diffraction (XRD) show the loss of structural water at an annealing temperature of ca.200 deg C.Structural water aids in gas generation upon reaction,promoting convective heat transfer and better performance.Its removal leads to the observed decrease in reaction rate at annealing temperatures up to 200 deg C.At more severe annealing conditions,structural phase transformations and morphological changes may account for the continued decrease reaction rate.These changes are under investigation by TGA,XRD,EM,and Brunauer,Emmet,Teller surface area measurement to elucidate the mechanistic reason for reactivity changes.
机译：钨三氧化物作为亚稳态分子复合材料（MICS）中金属的氧化剂是感兴趣的，其可用于这种应用的反应性纳米级粉末作为电匹配和枪引物.Smaller颗粒通常导致这类能量的快速反应速率材料，我们使用湿化学合成纳米级WO_3 _ H2O。通过电子显微镜（EM）分析约1 oonm×7nm血小板形态。甲氨铵溶解在酸中，除了蒸馏水外沉淀钨酸。将所得粉末干燥并退火。当使用用纳米级铝配制时，观察到的退火温度影响峰值压力和燃烧速率的峰值压力，因为纳米级铝作为燃料。脉络条件包括环境空气气氛和温度范围为100℃至600将持续时间为1小时至15小时的持续时间。Peak压力和峰值加压率从最大程度降低Y 250 psi和17 psi / microSecond，分别为50psi和0.7 psi / microSecond，随着退火持续时间和温度的增加。速度从500 m / s降低至180 m / s，也随着退火持续时间和温度的增加。热标测分析（TGA）和X射线衍射（XRD）显示在Ca.200℃的退火温度下的结构水损失。在反应后的气体产生，促进对流传热和更好的性能。删除导致观察到退火温度下的反应速率降低，高达200℃，更严重的退火条件，结构相变性和形态学变化可能持续降低反应率.TTGA，XRD，EM和Brunauer正在调查， Emmet，柜台面积区域测量阐明了反应性改变的机械原因。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号