Effect of Confining Pressure on Impact Reaction Threshold of Aluminum/Polytetrafluoroethylene Reactive Material

An impact reaction experiment is conducted with a modified split Hopkinson pressure bar (SHPB) apparatus to study the reaction threshold of aluminum/polytetrafluoroethylene (Al/PTFE) reactive materials under confining pressure. The dynamic compression behavior, impact damage characteristics, and impact reaction threshold of the Al/PTFE reactive material under the confining pressure are investigated. The results have presented that confining pressure makes the specimens suffer triaxial loading and improves the dynamic compressive strength of Al/PTFE reactive materials from 36.8 MPa (impact velocity is 14.64 m s⁻¹) to 62.7 MPa (14.80 m s⁻¹). Besides, the fractal dimension of the posttest specimen is decreased by confining pressure, which has proved that the confining pressure hinders damage under impact loading. Moreover, the impact reaction experiment demonstrates that the confining pressure increases the threshold of Al/PTFE, and the minimum specific incident energy for the reaction of the T10 (molding pressure is 10 MPa) specimen increases from (Formula presented.) to (Formula presented.). This research not only reveals that Al/PTFE can be reacted by impact loading at confining pressure but also clarifies that confining pressure limits the impact damage of the Al/PTFE reactive material and increases the reaction threshold.