Al/PTFE活性材料冲击载荷作用下响应特性研究

To investigate the response characteristics of aluminum/polytetrafluoroethylene (Al/PTFE) reactive materials under shock loading, the Al powder with the diameter of 10 μm and the PTFE powder with the diameter of 15 μm were mixed. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis were performed to ensure the uniformity and reactivity of the Al/PTFE mixed powders. The Al/PTFE specimen was prepared by using a cold pressing technique. The density of the Al/PTFE materials was 1.92 g/cm³. The Lagrangian experiment was designed to understand the response characteristics of the Al/PTFE specimen under shock loading. PBX8701 was used to produce high pressure. The shock loading was attenuated after passing an aluminum partition and acted on the specimen. Four block specimens with the sizes of \begin{document}$\varnothing$\end{document} 50 mm×3 mm were used, and manganin piezo-resistance gauges were mounted at the top surface and the end surface of the specimens to measure the pressure. It should be emphasized that the thickness of the aluminum partition was set to be 5 and 10 mm to control the input pressure acting on the specimens. In these two cases, the pressure and the shock velocity were analyzed. The measurement shows that both the pressure and the shock velocity are attenuated. The Lee-Tarver ignition and growth model was used to simulate the Lagrangian experiment by AUTODYN. The parameters in the model were validated by comparing the simulation and the experiment. Further, the Lagrangian experiment for the 500-mm-long Al/PTFE specimen was simulated. The results show that when the shock wave propagates through a long distance, although at the beginning the pressure and the velocity reduce quickly, up to some distance, the pressure and the velocity are close to a constant value around 1.3 GPa and 2180 m/s, respectively. The reaction was also analyzed. At the beginning, the value can be up to around 0.48 due to the high pressure. As the distance increases to 450 mm, the value reduces to 0.17. These results demonstrate that under the shock, the energy release of the Al/PTFE specimens prevents the energy dissipation during the shock wave propagation.