Study on penetration performance and mass abrasion characteristics of Zr-based alloy projectiles penetrating concrete target

To clarify the penetration performance and mass loss mechanism of Zr-based alloy projectiles, penetration tests into concrete targets were conducted using Zr-based alloy and 30CrMnSiNi2A steel projectiles at velocities ranging from 500 to 1000 m/s. The results showed that the penetration performance of the Zr-based alloy projectile was not significantly different from that of the steel projectile. Subsequently, macroscopic and microscopic characterization of the residual projectiles was performed through three-dimensional scanning, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) analysis. It was revealed that the mass loss of the Zr-based alloy projectile was contributed by both the nose and shank sections. Under the combined effects of high temperature and high stress during penetration, a distinct layered structure was formed in the surface layer of the projectile, extending from the interior outward and consisting of a molten zone, a plastically deformed zone, and an original microstructural zone. In addition, grain refinement and an increase in dislocation density were observed in the near-surface regions. The mechanical property evolution of the surface material was jointly influenced by thermal softening and grain refinement. The mass loss of the Zr-based alloy projectile was determined to result from the synergistic action of multiple mechanisms, including aggregate abrasion, thermal melting, and microstructural refinement. Finally, a projectile contour recession model was developed based on a thermal melting model and with consideration of the projectile material hardness. The maximum relative error between the predicted penetration depth and the experimental results was 8.79%, and a good agreement was observed between the calculated contour and the 3D-scanned profile, confirming the consistency between the model and the experimental data. The study provided theoretical basis and experimental support for the application of Zr-based alloys in warheads and the optimization of their penetration performance.