Controlling Shock-Induced Energy Release Characteristics of PTFE/Al by Adding Oxides

Polytetrafluoroethylene (PTFE)/aluminum (Al)-based energetic material is a kind of energetic material with great application potential. In this research, the control of the shock-induced energy release characteristics of PTFE/Al-based energetic material by adding oxides (bismuth trioxide, copper oxide, molybdenum trioxide, and iron trioxide) was studied by experimentation and theoretical analysis. Ballistic impact experiments with impact velocity of 735~1290 m/s showed that the oxides controlled the energy release characteristics by the coupling of impact velocities and oxide characteristics. In these experiments, the overpressure characteristics, including the quasi-static overpressure peak, duration, and impulse, were used to characterize the energy release characteristics. It turned out that when the nominal impact velocity was 735 m/s, the quasi-static overpressure peak of PTFE/Al/MoO₃ (0.1190 MPa) was 1.99 times higher than that of PTFE/Al (0.0598 MPa). Based on these experimental results, an analytical model was developed indicating that the apparent activation energy and impact shock pressure dominated the energy release characteristic of PTFE/Al/oxide. This controlling mechanism indicated that oxides enhanced the reaction after shock wave unloading, and the chemical and physical properties of the corresponding thermites also affected the energy release characteristics. These conclusions can guide the design of PTFE-based energetic materials, especially the application of oxides in PTFE-based reactive materials.