Abstract In order to reveal the influence of sintered and unsintered aluminum/polytetrafluoroethylene (Al/PTFE) reactive material on heat conduction, ignition and deflagration characteristics under the condition of thermal loading, the sintered and unsintered samples prepared by molding process are heated by acetylene flame as heat source. The heat conduction and deflagration behaviors of samples are measured synchronously by infrared thermal imager and high-speed camera before and after ignition. Meanwhile, combining with the three-dimensional differential equation of heat conduction in cylindrical coordinate system, the temperature gradient, heat flux and ignition moments during the process of heat conduction are solved by numerical simulation. The results show that the two kinds of samples both undergo the evolutions of temperature gradient and thermal shock wave induced by temperature gradient. The instantaneous energy accumulation caused by thermal shock wave promotes the samples to deflagrate, and the heat conduction durations before ignition, ignition temperature of sintered sample are both smaller than that of unsintered sample. The micro-morphologies before ignition indicate that the unsintered sample needs to accumulate more energy to achieve deflagration. The deflagration reaction extent of unsintered sample is more intense than that of sintered sample, however, the deflagration durations of sintered sample lasts longer. The maximum flame area of unsintered sample is 30.6% larger than that of the sintered sample, and the maximum temperatures of the flame core of sintered and unsintered sample are 1284 K and 1425 K, respectively.

中文翻译：

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温度梯度下热冲击波诱导铝/聚四氟乙烯的热传导和爆燃行为

摘要 为了揭示烧结和未烧结铝/聚四氟乙烯（Al/PTFE）反应材料在热负荷条件下对热传导、点火和爆燃特性的影响，采用乙炔火焰加热成型工艺制备的烧结和未烧结样品。作为热源。红外热像仪和高速摄像机在点火前后同步测量样品的热传导和爆燃行为。同时，结合圆柱坐标系中的三维热传导微分方程，通过数值模拟求解了热传导过程中的温度梯度、热通量和点火力矩。结果表明，两种样品均经历了温度梯度和由温度梯度引起的热冲击波的演变。热冲击波引起的瞬时能量积累促使样品发生爆燃，其点火前的热传导持续时间、烧结样品的点火温度均小于未烧结样品。点火前的微观形貌表明，未烧结的样品需要积累更多的能量才能实现爆燃。未烧结样品的爆燃反应程度比烧结样品强烈，但烧结样品的爆燃持续时间更长。未烧结试样的最大火焰面积比烧结试样大30.6%，