Al-PTFE (aluminum-polytetrafluoroethene) is regarded as one of the most promising reactive materials (RMs). In this work, Ni (Nickel) was added to Al-PTFE composites for the purpose of improving the energy density and damage effect. To investigate the thermal behavior, mechanical properties and reaction characteristics of the Al-Ni-PTFE composites, an Al-PTFE mixture and an Al-Ni mixture were prepared by ultrasonic mixing. Six types of Al-Ni-PTFE specimens with different component mass ratios were prepared by molding sintering. Simultaneous thermal analysis experiments were carried out to characterize the thermal behavior of the Al-PTFE mixture and the Al-Ni mixture. Quasi-static compression tests were performed to analyze the mechanical properties and reaction characteristics of the Al-Ni-PTFE specimens. The results indicate that the reaction onset temperature of Al-Ni (582.7 °C) was similar to that of Al-PTFE (587.6 °C) and that the reaction heat of Al-Ni (991.9 J/g) was 12.5 times higher than that of Al-PTFE (79.6 J/g). With the increase of Ni content, the material changed from ductile to brittle and the strain hardening modulus and compressive strength rose first and then subsequently decreased, reaching a maximum of 51.35 MPa and 111.41 MPa respectively when the volume fraction of Ni was 10%. An exothermic reaction occurred for the specimens with a Ni volume fraction no more than 10% under quasi-static compression, accompanied by the formation of Ni-Al intermetallic compounds. In the Al-Ni-PTFE system, the reaction between Al and PTFE preceded the reaction between Al and Ni and the feasibility of increasing the energy density and damage effect of the Al-Ni-PTFE reactive material by means of Ni-Al reaction was proved.

To investigate the effect of the addition of poly (vinylidene fluoride) (PVDF) on nanothermites, Al/MoO₃/PVDF energetic nanocomposites were prepared using electrospraying method. As a control group, Al/MoO₃ was also designed. Then, both samples were tested by FE-SEM, XRD and TG-DSC. TG-DSC results showed that the Al/MoO₃/PVDF energetic nanocomposites released more than 934.0 J g⁻¹ with two obvious exothermic peaks. Compared with the control group of 800.7 J g⁻¹ heat, it changed the thermal performance to some extent. There were Mo₂C among the residues products after the reaction via XRD. The activation energy (Ea) was analyzed using the Kissinger method under different heating rates by DSC. The addition of PVDF reduced the Ea of the thermites. To explore the combustion performance, a preliminary experiment was designed. The Al/MoO₃/PVDF energetic nanocomposites were easier to ignite and the burning was more durable, which was significant in solid propulsion and applications requiring extended combustion time.

As a novel energetic material with quite a high energy density, titanium hydride (TiH₂) was introduced into a polytetrafluoroethylene/aluminum (PTFE/Al) reactive material system for the first time. The effects of TiH₂ on the reaction energy, dynamic mechanical responses, and reaction properties of the composites were investigated through adiabatic bomb calorimeter, split-Hopkinson pressure bar, and drop-weight experiments. The results show that the reaction heat of the composites improved significantly as the content of TiH₂ increased. Under dynamic compression, these composites show obvious strain hardening and strain rate hardening effects. Besides, a certain amount of TiH₂ granules helps to improve the material’s compressive strength, and the maximum would even reach 173.2 MPa with 5% TiH₂ percentage, 10.1% higher than that of PTFE/Al. Mesoscale images of the samples after dynamic compression indicate that interface debonding between the particles and PTFE matrix and the fracture of the PTFE matrix are the two major mechanisms resulting in the material’s failure. In addition, the drop-weight experiments indicate that the material’s impact sensitivities are sensitive to the content of TiH₂, which would be increased to within 20% of the content of TiH₂ compared with PTFE/Al, and the reaction degree is also improved to within 10% of the content of TiH₂. The retrieved reaction residues after drop-weight experiments imply that the reaction is initiated at the edges of the samples, indicating a shear-induced initiation mechanism of this kind of reactive material.

A series of impact fuel tank experiments are carried out through the ballistic impact method. The ignition abilities of Bi₂O₃-reinforced PTFE/Al reactive material, metal aluminum, and inert metal steel are compared and analyzed, and the ignition mode of kerosene is explored when PTFE/Al/Bi₂O₃ impacts the fuel tank at different velocities. The results offer that PTFE/Al/Bi₂O₃ reactive material has outstanding ignition ability, and the order for ignition ability is PTFE/Al/Bi₂O₃ reactive material, metal aluminum, and inert metal steel. The kerosene content of the fuel tank has a significant impact on the ignition effect. The ignition effect of PTFE/Al/Bi₂O₃ reactive material impacting the fuel tank filled with 50% kerosene is weaker than that impacting the full tank. Under different impact velocities, PTFE/Al/Bi₂O₃ reactive materials display diverse ignition modes for kerosene: kerosene is directly ignited by the flame in the reverse reaction zone under low-velocity conditions, while high-temperature-activated reactive fragments are the ignition heat source of high-velocity conditions.

To study the effect of the addition of potassium perchlorate (KClO₄) on the performance of nano thermites, Al/Bi₂O₃ nano thermites with different mass fraction (wt%) of KClO₄ was made by ultrasonic dispersion method. Then, all samples were tested by SEM, DSC and rapid excitation ignition. DSC results showed Al/Bi₂O₃/10 wt%KClO₄ had the highest heat release. Compared with Al/Bi₂O₃, the heat release increased by 28.32%. The results of activation energy calculations showed Al/Bi₂O₃/30 wt%KClO₄ had the lowest activation energy (Ea). Its activation energy was reduced by 30%, mere about 149.17 KJ mol⁻¹. Finally, it can be seen from the combustion situation that the addition of KClO₄ reduced the intensity of burning. This work found a way to increase the heat release or reduce the activation energy of nano thermites by controlling the amount of KClO₄ added.