Effect of Microstructure on Energy Release Characteristics of Al/Ni Energetic Structural Material Prepared by Cold Spraying

Al/Ni energetic structural material with both high strength structural properties and high energy release functional properties can undergo a strong exothermic reaction under heating or impact loading conditions. In order to investigate the influence of microstructure on the mechanical properties and energy release characteristics of the Al/Ni energetic structural material, the materials with different Ni contents were prepared by cold spraying. With the increase of Ni particles, the microstructure inside the energetic structural material gradually changes from a continuous network structure of Al to a continuous network structure of Ni. The contact between Ni particles will make the stress transfer more uniform during the compression process of the energetic structural material, which enhances their strength. The results of heat-induced exothermic and shock-induced energy release show that the Al/Ni energetic structural material exhibits the best exothermic performance when Ni particles are uniformly dispersed and there are enough Al and Ni to make the material completely transform into the AlNi phase. The increase in the contact interface between Al and Ni particles facilitates the occurrence of a solid/solid reaction exothermic reaction between Al and Ni as well as the diffusion of Ni into the Al melt to generate the AlNi phase. The formation of the Ni continuous phase will lead to a reduction in the contact interface between Al and Ni, as well as an increase in porosity, which will result in a decrease in the amount of heat released during the diffusion reaction. This study will provide insights into the preparation of an Al/Ni energetic structural material with excellent properties.