Moderating jet coherency to enhance the aftereffect damage while retaining desired penetration capability of shaped charge liners with Ti-Zr-Nb-Al energetic high-entropy alloys

Enhancing aftereffect damage while maintaining enough penetration capability has emerged as a critical challenge in the development of shaped charge liners (SCLs). This work investigates the dynamic mechanical properties, jet morphologies, static penetration, and aftereffect damage behaviors of three energetic high-entropy alloys (E-HEAs), two of which (H1 and H2) exhibit single-phase body-centered cubic (BCC) structures and one exhibits a dual-phase BCC+ α₂ structure. The single-phase alloys maintain excellent deformability under both dynamic compression (21–44 % fracture strain) and dynamic tensile (14–21 %) loadings, while the dual-phase S1 alloy exhibits superior compressive deformability (31 %) but negligible tensile plasticity (2 %). As a result, all SCLs form coherent initial jets, but S1 rapidly fragments into particles during elongation, achieving a comet-like jet tip morphology with a large head diameter (0.3 charge diameter, CD). Both S1 and H1 SCLs, with the same composition, successfully penetrate armor steel targets, but the aftereffect damage of the S1 SCL is greater due to its dispersed jet particles after penetration (67 holes and 213 craters for S1 vs. 23 holes and 113 craters for H1). Meanwhile, the post-penetration jets cause significant high-temperature damage, attributed to the promotion of combustion generated by the reactive elements in the E-HEAs. This work demonstrates that tuning dynamic plasticity under different load conditions of E-HEAs can effectively balance the penetration and aftereffect performance of SCLs.