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Ballistic impact experiments are conducted on a cast Mg-6Gd-3Y-0.5Zr alloy using spherical projectiles under a wide range of impact velocities. Penetration processes are captured by high-speed camera. Postmortem target samples are characterized via three-dimensional laser scanning, metallographic microscopy, scanning electron microscopy and electron backscatter diffraction. Shear bands and twinning dominate the deformation of Mg-6Gd-3Y-0.5Zr near the crater, and texture changes due to compression caused by cavity expansion. For instance, a finite element model based on Johnson–Cook constitutive model and Mie–Grüneisen equation of state is established. Four dimensionless quantities related to craters and projectiles are defined. An analytical model based on dynamic cylindrical cavity expansion model is applied considering projectile deformation, and consistent well with experimental and simulated results over the entire incident velocity range. [Display omitted] • Ballistic impact experiments are conducted on cast Mg-6Gd-3Y-0.5Zr alloy. • Shear bands and twins dominate deformation of Mg-6Gd-3Y-0.5Zr near the crater. • Finite element model is established and consistent with experimental results. • A cylindrical cavity expansion model is derived considering projectile deformation. [ABSTRACT FROM AUTHOR]

Ballistic impact experiments are conducted to investigate high-speed penetration of polycarbonate by steel spheres at impact velocities ranging from ∼ 600 to 2400 m s−1. High-speed photography is applied to capture the penetration processes, including projectile trajectories and cavity/damage evolution. Postmortem projectiles are characterized with three-dimensional laser scanning, and postmortem targets, with optical imaging and micro computed tomography. The maximum penetration depth varies nonmonotonically with impact velocity v i , and decreases with increasing v i above about 1777 m s−1. With increasing v i , the damage of polycarbonate targets increases significantly in amplitude and volume. The damage networks, consisting of cracks and voids, exhibit fractal features with similar fractal dimensions. At low v i , plate-shaped cracks are formed in the cavity, while needle-shaped cracks along with a large amount of melting-induced small voids, at high v i. Numerical simulations of impact penetration of polycarbonate reproduces well the experimental observations. Considering projectile distortion, a modified Poncelet model is derived to describe the nonmonotonic relation between the maximum penetration depth and v i. [Display omitted] • Ballistic impact experiments and modeling on polycarbonate with steel spheres. • Maximum penetration depth varies non-monotonically with impact velocity. • Damage morphologies and mechanisms vary with impact velocity. • A modified Poncelet model derived considering projectile distortion. [ABSTRACT FROM AUTHOR]