Theoretical Model for the Impact-Initiated Chemical Reaction of Al/PTFE Reactive Material

Lu, Guancheng; Li, Peiyu; Liu, Zhenyang; Xie, Jianwen; Ge, Chao; Wang, Haifu

doi:10.3390/ma15155356

Cited by 15 publications

(3 citation statements)

References 28 publications

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“…Thus, it is speculated that the impact reactivity can be attributed to a number of factors, including absorption of mechanical energy, sensitivity to activation, impact energy threshold, and the formation of adiabatic shear bands 31,32 . The non‐self‐sustaining reaction behavior of RSMs is divided into impact ignition and gas–solid chemical reactions, 33 and the gas–solid chemical reaction model of Al/PTFE is shown in Figure 12. Under high strain rate loading, some local hot‐spots formed around the pores due to the work of plastic deformation and collapse shear (Figure 12A).…”

Section: Resultsmentioning

confidence: 99%

Effects of different mass ratios on mechanical properties and impact energy release characteristics of Al/PTFE/W and Al/PTFE/CuO polymer composites

Xu,

Fang,

Chen

et al. 2024

Polymer Composites

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Aluminum/polytetrafluoroethylene (Al/PTFE) is an impact‐initiated material that is extensively utilized in military and civilian applications due to its insensitivity, high energy density and ease of manufacturing. To increase both its compressive strength and energy density, Al/PTFE was doped with various amounts of W and CuO particles. These polymer composites exhibit elastoplastic properties, as well as significant strain hardening and strain‐rate hardening during compression deformation. At a strain rate of 5000 s−1, the compressive strength of the Al/PTFE/W and Al/PTFE/CuO specimens with an additive content of 30% reaches a peak of 194.1 and 189.2 MPa, which corresponds to an increase of 40.3% and 36.8%, respectively, compared with the compressive strength of Al/PTFE (138.3 MPa). The homogeneous bonding strength between the additives and PTFE and the fact that the elastic PTFE nanofibers inhibit the extension of microcracks are the main mechanical strengthening mechanisms. The reaction of the composites under high‐speed impact is violent and accompanied by sputtering sparks, and the reaction efficiency was determined using an improved drop‐hammer apparatus. As the W content increases, the impact reactivity of Al/PTFE/W decreases monotonically. However, as CuO content increases, the reaction intensity of Al/PTFE/CuO initially increases, and then decreases. At a CuO content of 30%, the energy release efficiency of Al/PTFE/CuO reaches its maximum (10.49%), which is 84.4% higher than that of Al/PTFE. TG‐DSC and XRD tests were performed to analyze the pyrolysis process and elucidate the reaction mechanism. A gas–solid chemical reaction model was developed, and the reactivity arises from multiple factors.Highlights Typical elastoplastic characteristics as well as strain hardening and strain‐rate hardening were observed. The mechanical strengthening effect of W particles is higher than that of CuO particles of Al/PTFE specimen. The addition of W particles decreases the impact reactivity, but the addition of CuO particles improves the energy density of Al/PTFE. The reaction efficiency of Al/PTFE/CuO reaches a peak of 10.49%, which increased by 84.4% compared with that of Al/PTFE.

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Section: Resultsmentioning

confidence: 99%

Effects of different mass ratios on mechanical properties and impact energy release characteristics of Al/PTFE/W and Al/PTFE/CuO polymer composites

Xu,

Fang,

Chen

et al. 2024

Polymer Composites

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“…The research results would be useful for the numerical studies, design, and application of reactive materials. Lu et al [ 12 ] proposed an impact-initiated chemical reaction model to describe the ignition and energy release behavior of Al/PTFE RM. The hotspot formation mechanism of pore collapse was first introduced to describe the decomposition process of PTFE.…”

Section: Shock-induced Chemical Reactionmentioning

confidence: 99%

Editorial for the Special Issue “Materials under High Pressure”

Wang,

Zheng,

Qiao

et al. 2023

Materials

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“…Cai [ 6 ] analyzed the effect of material porosity on the temperature rise of Al/PTFE, suggesting that collapsing and closing of internal pores under impact loads lead to rapid temperature increases and hotspot formation, thereby initiating reactions. Lu [ 7 ] proposed a theoretical model to describe the behavior of impact-induced chemical reactions: under impact, hotspots are formed in the PTFE matrix. When the temperature of these hotspots reaches the decomposition temperature of PTFE, CF 2 gas is released.…”

Section: Introductionmentioning

confidence: 99%

Microscopic Chemical Reaction Mechanism and Kinetic Model of Al/PTFE

Guo,

Li,

Chen

et al. 2024

Polymers

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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.

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Theoretical Model for the Impact-Initiated Chemical Reaction of Al/PTFE Reactive Material

Cited by 15 publications

References 28 publications

Effects of different mass ratios on mechanical properties and impact energy release characteristics of Al/PTFE/W and Al/PTFE/CuO polymer composites

Effects of different mass ratios on mechanical properties and impact energy release characteristics of Al/PTFE/W and Al/PTFE/CuO polymer composites

Editorial for the Special Issue “Materials under High Pressure”

Microscopic Chemical Reaction Mechanism and Kinetic Model of Al/PTFE

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