Enhancement of energy release performance of Al–Ni composites by adding CuO

Al–Ni composites, which have excellent energy densities and mechanical properties, are promising novel energetic materials for improving the damaging effects of ammunition. To enhance their energy release performance under impact loading, CuO was introduced to form the thermite. The results of differential scanning calorimetry (DSC), heat treatment, and ballistic tests indicated that Al and Ni were more prone to donate their free electrons after the addition of CuO. A decrease in the number of free electrons as well as the weak metal-oxygen bonds at the Al/Ni interfaces caused by the thermal decomposition of CuO, impeded the activity of the Al–Ni intermetallic formation reaction, increasing its onset temperature from 766 K to 820 K. The reduced difference in the onset temperatures for the intermetallic formation and thermite reactions caused the thermite reaction between Al and CuO to be ignited by the Al–Ni intermetallic formation reaction. The overlap of these two exothermic reactions greatly improved the reaction intensity, and then accelerated the oxidation of Al and Ni, finally enhancing the energy release performance during high-speed impact. This work demonstrated that the energy release performance of Al–Ni composites can be effectively modulated by introducing a metal oxide. Moreover, the effect of a metal oxide on the energy release behavior of Al–Ni composites accounted for the interaction of aluminum and nickel with the added copper oxide.