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In this paper, the energy release mechanism of shock-induced chemical reaction (SICR) of Al/Ni composites was investigated. The Al/Ni composites with two additives, namely Teflon (PTFE) and copper (Cu), were considered in both theoretical calculations and experiments to investigate their influence on SICR characteristics of Al/Ni composites system. Assuming the SICR process is controlled by shock temperature rising in the materials, the reaction efficiency of Al/Ni composites was calculated by Arrhenius reaction rate and Avrami−Erofeev reaction models. Hugoniot curves and the temperature rise under shock compression were calculated to analyze the mechanism of the influence on SICR characteristics by additives. Impact-initiated experiments of Al/Ni composites were carried out to study SICR characters at various impact velocities. The parameters of SICR model were determined by using corresponding experimental results. The calculation results showed that for the SICR process of Al/Ni, the critical shock temperature for initiation of SICR (T cr = 452 K) and the apparent activation energy (E a = 90.9 kJ/mol) appeared much lower than the values of normal ignition process (T ig = 990 K, E iga = 351.6 kJ/mol). The additive of Cu decreased the shock temperature significantly in Al/Ni composites, which led to the increase of critical shock conditions for initiation of SICR and the decrease of reaction efficiency at the same shock pressure. On the other hand, the additive of PTFE to Al/Ni composites decreased the critical shock conditions for initiation of SICR and increased the chemical reaction efficiency by participating in the reactions.

High-entropy alloys (HEAs) are promising structural materials due to their excellent comprehensive performances. The use of mechanically alloyed powders to deposit HEA coatings through atmospheric plasma spraying (APS) is an effective approach that can broaden the application areas of the HEAs. In this paper, a ductility–brittleness AlCoCrFeNiSi system was chosen as an object of study, and the detailed evolution of the surface morphology, particle size distribution, and microstructure of the powder during mechanical alloying was investigated. An AlCoCrFeNiSi HEA coating was deposited using powder milled for 10 h, which can be used as an ideal feedstock for APS. The surface morphology, microstructure, microhardness, and wear behavior of the coating at room temperature were investigated. The results showed that as the milling time increased, the particle size first increased, and then decreased. At the milling time of 10 h, simple body-centered cubic (BCC) and face-centered cubic (FCC) solid solution phases were formed. After spraying, the lamellar structure inside a single particle disappeared. An ordered BCC phase was detected, and the diffraction peaks of the Si element also disappeared, which indicates that phase transformation occurred during plasma spraying. A transmission electron microscopy analysis showed that nanometer crystalline grains with a grain size of about 30 nm existed in the APS coating. For the coating, an average microhardness of 612 ± 41 HV was obtained. Adhesive wear, tribo-oxidation wear, and slight abrasion wear took place during the wear test. The coating showed good wear resistance, with a volume wear rate of 0.38 ± 0.08 × 10−4 mm3·N−1·m−1, which makes it a promising coating for use in abrasive environments.