Synergistic and differentiated mechanisms of composite fuels in thermites: A case study of Ni-modified Al/Fe₂O₃ prepared via electrophoretic deposition

To investigate the effect of Ni on the performance of Al/Fe₂O₃ thermite, Ni was introduced into the system, and an Al/Ni/Fe₂O₃ ternary composite thermite (Al/Ni/Fe₂O₃-EPD) was successfully fabricated via electrophoretic deposition (EPD). A systematic comparison was conducted with physically mixed (PM) samples (Al/Ni/Fe₂O₃-PM). The morphology, structure, and thermal behavior of the samples were characterized by SEM-EDS, XRD, and TG-DSC analyses. The results indicate that the EPD-fabricated samples exhibit a dense structure and a more uniform component distribution, whereas the physically mixed samples show pronounced agglomeration of Ni. Thermal analysis demonstrates that the incorporation of Ni enhances the thermal stability of the thermite but suppresses the energy release process. Non-isothermal kinetic analysis further reveals that Ni reduces the overall reaction activity of the system, and EPD does not lead to a reduction in the activation energy of the Al/Ni/Fe₂O₃ system. Mechanistic studies indicate that the reaction of Al/Ni/Fe₂O₃-EPD in air involves the thermite reaction between Al and Fe₂O₃, the direct oxidation of Al, Ni, and Fe, and the alloying reaction between Al and Ni. This work systematically evaluates the effects of the EPD process and Ni fuel addition on the performance of the Al/Fe₂O₃ thermite system. By comparing the results with reported Al/B/Fe₂O₃ and Al/Ti/Fe₂O₃ systems, the study elucidates the synergistic and differentiated mechanisms of various composite fuels in thermite reactions, providing useful insights into the structural design and mechanistic investigation of multicomponent composite thermites.