Study on the effect of Zr-based reactive casing on explosion enhancement and fuel ignition

To investigate the explosive energy release of Zr-based reactive material (Zr-RM) casings and the ignition effect of fragments driven by the explosion on fuel, casings composed primarily of zirconium (Zr), copper (Cu), nickel (Ni), aluminum (Al), and ytterbium (Y) were fabricated using alloy melting and casting techniques. The casings mentioned above had an outer diameter of 40 mm, a height of 80 mm, and a wall thickness of 5 mm. For comparison of subsequent damage effects, steel casings made of 45 steel with the same dimensions and mass were also prepared. Both types of casings were filled with JH-2 explosive charges. The charged structures were placed on a polyvinyl chloride pipe stand 1.5 m above the ground, and a fuel box containing 2.5 L of gasoline was positioned 2.0 m away from the explosion center. During the explosion-driven tests, a high-speed camera was utilized to capture the formation and propagation of the explosion fireball, the shockwave, and the impact process of casing fragments on the fuel tank. The fireball duration, shockwave velocity, and fragment impact effects were measured and analyzed. Additionally, the ignition and destruction effects of the fragments on the fuel were observed and recorded. The experimental results demonstrate that, when compared to steel casings of equal mass, Zr-RM casings under explosion-driven conditions exhibit a longer duration of firelight and faster shockwave velocities. Specifically, the fireball duration of Zr-RM casings is approximately 25.84 times that of steel casings, and the shockwave velocity is roughly 1.17 times faster. Zr-RM casings exhibit an enhancement effect on air shockwaves under explosion-driven conditions. Fragments of different materials cause structural damage to fuel tanks, including perforation and plastic deformation. After piercing the fuel tank, the reactive material ignites the fuel inside, demonstrating the ability to ignite gasoline. On the contrary, steel casings of equal mass do not ignite the fuel within the tank. This research provides a reference for the application of Zr-RM casing warheads.