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In order to study the microscopic reaction mechanism and kinetic model of Al/PTFE, a reactive force field (ReaxFF) was used to simulate the interface model of the Al/PTFE system with different oxide layer thicknesses (0 Å, 5 Å, 10 Å), and the thermochemical behavior of Al/PTFE at different heating rates was analyzed by simultaneous thermal analysis (TG-DSC). The results show that the thickness of the oxide layer has a significant effect on the reaction process of Al/PTFE. In the system with an oxide layer thickness of 5 Å, the compactness of the oxide layer changes due to thermal rearrangement, resulting in the diffusion of reactants (fluorine-containing substances) through the oxide layer into the Al core. The reaction mainly occurs between the oxide layer and the Al core. For the 10 Å oxide layer, the reaction only exists outside the interface of the oxide layer. With the movement of the oxygen ions in the oxide layer and the Al atoms in the Al core, the oxide layer moves to the Al core, which makes the reaction continue. By analyzing the reaction process of Al/PTFE, the mechanism function of Al/PTFE was obtained by combining the shrinkage volume model (R3 model) and the three-dimensional diffusion (D3 model). In addition, the activation energy of Al/PTFE was 258.8 kJ/mol and the pre-exponential factor was 2.495 × 1015 min−1. The research results have important theoretical significance and reference value for the in-depth understanding of the microscopic chemical reaction mechanism and the quantitative study of macroscopic energy release of Al/PTFE reactive materials. [ABSTRACT FROM AUTHOR]

With the improvement of protection technology, the damage power of conventional penetrators has become increasingly inferior. Reactive material is a new type of energetic material, which has strong energy release capabilities under high-velocity-impact conditions. In this paper, the reactive materials were put into the penetrator, and its penetration characteristics were studied. First, the penetrator with enhanced lateral effect (PELE) projectile structure with better penetration capability was obtained by numerical simulation. Then, based on the established polytetrafluoroethylene (PTFE)/Al reactive material reaction model, the numerical simulation and experimental research of the PELE projectile with a reactive inner core penetrating the target were carried out. The results show that the simulation results are in good agreement with the experimental results, which verifies the confidence of the numerical simulation. The PELE projectile had a significant increase in power with the use of a truncated conical head and reactive materials. The residual velocity of the truncated cone PELE projectile increases by 8.41–21% over conventional PELE projectiles. Its damage range is 43% higher than that of conventional penetrators. The simulation method and the conclusions obtained in this paper can provide support and reference for further research on reactive materials and on effectively improving the damage power of the penetrator. [ABSTRACT FROM AUTHOR]

In this paper, the reaction characteristic of a novel reactive material, which introduced bismuth trioxide (Bi2O3) into traditional polytetrafluoroethylene/aluminum (PTFE/Al), is studied. The effect of Bi2O3 with different content and particle size on the reaction behaviors of PTFE/Al/Bi2O3 are investigated by drop-weight test and X-ray diffractometer (XRD), including impact sensitivity, energy release performance under a certain impact, and reaction mechanism. The experimental results show that the content of Bi2O3 increased from 0% to 35.616%, the characteristic drop height of impact sensitivity (H50) of PTFE/Al/Bi2O3 reactive materials decreased first and then increased, and the minimum H50 of all types of materials in the experiment is 0.74 times that of PTFE/Al, and the particle size of Bi2O3 affects the rate of H50 change with Bi2O3 content. Besides, with the increase of Bi2O3 content, both the reaction intensity and duration first increase and then decrease, and there is optimum content of Bi2O3 maximizing the reaction degree of the PTFE/Al/Bi2O3. Furthermore, a prediction model for the impact sensitivity of PTFE-based reactive material is developed. The main reaction products include AlF3, xBi2O3·Al2O3, and Bi. [ABSTRACT FROM AUTHOR]