• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Applied Physics >The role of microstructure refinement on the impact ignition and combustion behavior of mechanically activated Ni/Al reactive composites
【24h】

The role of microstructure refinement on the impact ignition and combustion behavior of mechanically activated Ni/Al reactive composites

机译：微结构细化对机械活化的Ni / Al反应性复合材料的冲击着火和燃烧行为的作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Metal-based reactive composites have great potential as energetic materials due to their high energy densities and potential uses as structural energetic materials and enhanced blast materials however these materials can be difficult to ignite with typical particle size ranges. Recent work has shown that mechanical activation of reactive powders increases their ignition sensitivity, yet it is not fully understood how the role of microstructure refinement due to the duration of mechanical activation will influence the impact ignition and combustion behavior of these materials. In this work, impact ignition and combustion behavior of compacted mechanically activated Ni/Al reactive powder were studied using a modified Asay shear impact experiment where properties such as the impact ignition threshold, ignition delay time, and combustion velocity were identified as a function of milling time. It was found that the mechanical impact ignition threshold decreases from an impact energy of greater than 500 J to an impact energy of ∼50 J as the dry milling time increases. The largest jump in sensitivity was between the dry milling times of 25% of critical reaction milling time (tcr) (4.25 min) and 50% tcr (8.5 min) corresponding to the time at which nanolaminate structures begin to form during the mechanical activation process. Differential scanning calorimetry analysis indicates that this jump in the sensitivity to thermal and mechanical impact is dictated by the formation of nanolaminate structures, which reduce the temperature needed to begin the dissolution of nickel into aluminum. It was shown that a milling time of 50%–75% tcr may be near optimal when taking into account both the increased ignition sensitivity of mechanical activated Ni/Al and potential loss in reaction energy for longer milling times. Ignition delays due to the formation of hotspots ranged from 1.2 to 6.5- #x2009;ms and were observed to be in the same range for all milling times considered less than tcr. Combustion velocities ranged from 20–23 cm/s for thermally ignited samples and from 25–31 cm/s for impacted samples at an impact energy of 200–250 J.
机译：金属基反应性复合材料由于其高能量密度以及作为结构性含能材料和增强爆炸材料的潜在用途而具有作为含能材料的巨大潜力，但是这些材料在典型的粒径范围内可能难以点燃。最近的工作表明，反应性粉末的机械活化可提高其点火敏感性，但尚未完全了解由于机械活化的持续时间引起的微结构细化作用将如何影响这些材料的冲击点火和燃烧行为。在这项工作中，使用改进的Asay剪切冲击实验研究了压实的机械活化的Ni / Al反应粉末的冲击点火和燃烧行为，其中确定了诸如冲击点火阈值，点火延迟时间和燃烧速度等性质作为研磨的函数时间。结果发现，随着干磨时间的增加，机械冲击着火阈值从大于500 impactJ的冲击能降低到〜50 J的冲击能。灵敏度的最大跳跃是在临界反应研磨时间（t cr ）的25％（4.25 min）和50％t cr （8.5 min）的干磨时间之间对应于在机械活化过程中纳米层压结构开始形成的时间。差示扫描量热分析表明对热和机械冲击的敏感性的这种跳跃是由纳米层压结构的形成所决定的，纳米层压结构降低了开始将镍溶解到铝中所需的温度。结果表明，考虑到机械活化的Ni / Al的增加的点火敏感性和较长时间的研磨反应能量的潜在损失，50％–75％t cr 的研磨时间可能接近最佳。次。由于热点的形成而引起的点火延迟在1.2到6.5-x2009; ms之间，对于所有小于t cr 的研磨时间，观察到的延迟都在相同的范围内。在200–250 J的冲击能量下，热点燃样品的燃烧速度范围为20–23 cm / s，受影响样品的燃烧速度范围为25–31 cm / s。

著录项

  • 来源
    《Journal of Applied Physics》 |2013年第11期|1-7|共7页
  • 作者

    Mason B.A.; Groven L.J.; Son S.F.;

  • 作者单位

    School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA|c|;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

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