High-speed penetration of cast Mg-6Gd-3Y-0.5Zr alloy: Experiments and modeling

Abstract

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.