Energy release and damage effects of Ni–Al reactive jet in underwater environment

Reactive material liners demonstrate significant potential in underwater weaponry, yet dedicated studies on underwater reactive shaped charges remain scarce. This study investigates the underwater energy-release characteristics of cold-sprayed nickel–aluminum (Ni–Al) reactive jets and damage effects against spaced steel targets. All tests were conducted in a water-filled tank, and the results were compared with those of Cu jets. High-speed photography, pressure sensors, x-ray diffraction, and three-dimensional scanning were used. During penetration into the water without the spaced steel targets, the Ni–Al jet demonstrated penetration capability comparable to that of a Cu jet, along with superior velocity retention. In underwater spaced target tests, the Cu jet penetrated five plates and cratered the sixth, while the Ni–Al counterpart penetrated four plates and caused extensive plastic deformation on the fifth. The fifth plate exhibited substantially greater maximum deflection and displacement volume under Ni–Al impact compared to Cu impact. Furthermore, the Ni–Al jet generated significantly higher peak pressures than the inert Cu jet. These results demonstrate that the cold-sprayed Ni–Al jets synergistically integrate kinetic penetration with sustained chemical energy release, thereby enhancing the structural tearing and deformation damage inside the targets.