High speed 2-dimensional temperature measurements of nanothermite composites: Probing thermal vs. Gas generation effects
High speed 2-dimensional temperature measurements of nanothermite composites: Probing thermal vs. Gas generation effects
复制标题
纳米铝热剂复合材料的高速二维温度测量：探测热效应与气体产生效应
DOI：
10.1063/1.5021890
复制
发表时间：
2018
影响因子：
3.2
通讯作者：
M. Zachariah
中科院分区：
文献类型：
--
作者：
R. Jacob;D. Kline;M. Zachariah
本研究透过高速光谱、压力量测及高速彩色摄影高温量测，探讨亚稳态分子间复合物之反应动力学。Al/CuO和Al/Fe_2O_3/xWO_3（x为氧化剂摩尔比）共8种混合物。%）在恒定体积压力池中反应，作为调节气体释放和绝热温度的手段。气体释放，峰值压力和加压速率之间的直接相关性进行了观察，但它没有与温度相关。当WO 3作为化学计量的氧化剂含量的一部分而变化时，发现Al/Fe 2 O3/70%WO3实现了最高的压力和最短的燃烧时间，尽管混合物之间的温度相当恒定，这表明吸热的Fe 2 O3分解和更高的绝热火焰温度之间的相互作用由Al/WO 3反应维持在复合材料中。建议Al/WO 3的较低点火温度导致复合材料的引发，其较高的火焰温度增强了Fe 2 O3的气化，从而改善了平流和传播作为驱动反应的反馈回路的一部分。这种气体释放促进反应性的直接证据是通过反应的高速高温测量视频获得的。这些结果为纳米高能材料奠定了基础，这些材料可以通过精心选择的氧化剂混合物进行调整以适应特定的应用。
This work investigates the reaction dynamics of metastable intermolecular composites through high speed spectrometry, pressure measurements, and high-speed color camera pyrometry. Eight mixtures including Al/CuO and Al/Fe2O3/xWO3 (x being the oxidizer mol. %) were reacted in a constant volume pressure cell as a means of tuning gas release and adiabatic temperature. A direct correlation between gas release, peak pressure, and pressurization rate was observed, but it did not correlate with temperature. When WO3 was varied as part of the stoichiometric oxidizer content, it was found that Al/Fe2O3/70% WO3 achieved the highest pressures and shortest burn time despite a fairly constant temperature between mixtures, suggesting an interplay between the endothermic Fe2O3 decomposition and the higher adiabatic flame temperature sustained by the Al/WO3 reaction in the composite. It is proposed that the lower ignition temperature of Al/WO3 leads to the initiation of the composite and its higher flame temperature enhances the gasification of Fe2O3, thus improving advection and propagation as part of a feedback loop that drives the reaction. Direct evidence of such gas release promoting reactivity was obtained through high speed pyrometry videos of the reaction. These results set the stage for nanoenergetic materials that can be tuned for specific applications through carefully chosen oxidizer mixtures.