Enhanced Energetic Performances Based on Integration with the Al/PTFE Nanolaminates

Research on the Impact Initiation Behavior of PTFE/Al/Ni2O3 Reactive Materials

PTFE/Al reactive material is an energetic material that releases energy under impact conditions, resulting in a wide range of application prospects. In order to improve its damage ability—considering the higher heat of the reaction per unit mass when Ni2O3 is involved in the aluminothermic reaction—we designed and studied PTFE/Al/Ni2O3, a reaction material based on polytetrafluoroethylene (PTFE). We also designed two other kinds (PTFE/Al, PTFE/Al/CuO) for comparative study, with the mass fraction of the metal oxides added at 10%, 20%, and 30%, respectively. The quasi-static compression properties and impact initiation behavior of the material were investigated by a universal material testing machine and a drop hammer test. The reaction process of different materials under a high strain rate was recorded using a high-speed camera. The results show that with the increase in Ni2O3 content, the strength of the PTFE/Al/Ni2O3 reactive material shows an increasing trend followed by a decreasing trend. Among the three reactive materials, when the content of Al/Ni2O3 reaches 30 wt.%, the reaction duration is the longest (at 4 ms) and the reaction fireball is the largest. The addition of Ni2O3 is helpful to improve the reactivity and reaction duration of the PTEF/Al reactive material.

A comparative study on the mechanical and reactive behavior of three fluorine-containing thermites

Thermite serves as a kind of representative energetic material, which is extensively applied in the civil and military fields. In this paper, PTFE/Al/Fe₂O₃, PTFE/Al/MnO₂ and PTFE/Al/MoO₃, solid fluorine-containing thermite with different PTFE content, were successfully fabricated by referring to the traditional thermite and adding PTFE as a binder or matrix. Quasi-static compression tests were performed to investigate the mechanical and reactive behavior of fluorine-containing thermite. SEM and XRD were employed to analyze and characterize the energetic composites and reaction residuals. The results show that all types of fluorine-containing thermite exhibited different mechanical behavior. PTFE/Al/MnO₂ exhibited the lowest yield strength and strain hardening modulus, but the highest compressive strength and toughness. With the increase of PTFE content, the strength of fluorine-containing thermite improved. No reaction occurred when the PTFE content was 60 vol%, while fluorine-containing thermite with a PTFE content of 80 vol% experienced a severe exothermic reaction under quasi-static compression. The ignition of PTFE/Al/MoO₃ and PTFE/Al/Fe₂O₃ actually attributed to the reaction of Al and PTFE, and the reaction between Al and Fe₂O₃ or MoO₃ was not excited due to the insufficient input energy. The thermite reaction between Al and MnO_2, as well as the reaction of MnO₂ and PTFE, was induced because PTFE/Al/MnO₂ possessed excellent ductility and absorbed the most energy during compression, accompanied with the production of Mn and MnF₂.

Precisely Controlled Reactive Multilayer Films with Excellent Energy Release Property for Laser-Induced Ignition

Three types of reactive multilayer films (RMFs) were integrated to the energetic flyer plates (EFPs) by depositing TiO₂, MnO₂, and CuO onto aluminum films with different modulation periods using magnetron sputtering technology in this study. The effects of the laser ignition property and laser reflectivity on the RMFs and the thermal behavior of the RMFs were analyzed and compared with those of a single-layer Al film. A high-speed video, photonic Doppler velocimetry (PDV), and a thermal analysis were utilized to characterize the flame morphology, EFP velocity, and chemical thermal behavior, respectively. The surface reflectivities of the TiO₂/Al, MnO₂/Al, and CuO/Al layers were measured using laser reflectivity spectrometers. The results showed that RMFs with smaller modulation periods exhibited excellent laser ignition performances, and EFP with MnO₂/Al had the best performance. These RMFs achieved flame durations of 120-220 μs, maximum flame areas of 7.523-11.476 mm², and reaction areas of 0.153-0.434 mm² (laser-induced with 32.20 J/cm²). Flyer velocities of 3972-5522 m/s were obtained in the EFPs by changing the material and modulation period of the RMFs. Furthermore, the rate of the chemical reaction and laser energy utilization were also enhanced by reducing the modulation period and using different material. This behavior was consistent with a one-dimensional nanosecond-laser-induced plasma model. The RMFs of MnO₂/Al exhibited the highest level of energy release and promoted laser energy utilization, which could better improve the performance of laser ignition for practical application.