Effects of projectile material on high-speed penetration/perforation of Inconel 718 alloy plates: Experiments and simulations

We investigate the effects of projectile material on high-speed penetration/perforation of Inconel 718 alloy (IN718) plates. High-speed ballistic impact tests are conducted on 2 mm-thickness IN718 plates with 5-mm-diameter stainless steel 304 (SS304), Ti alloy TC4, and Al alloy AA1060 spherical projectiles. The impact processes are captured with high-speed photography. Optical and scanning electron microscopy and laser scan are conducted on recovered projectiles and targets. Finite element models of the ballistic impact are established based on the coupled Eulerian–Lagrangian algorithm with the Johnson–Cook constitutive model and failure criterion, and can well reproduce the experimental results. The experimental and simulated data related to projectile dynamics, and the geometries of postmortem projectiles and bullet holes are analyzed with phenomenological models. Projectile velocity evolution can be described with hydrodynamic models of penetration. Dimensional analysis reveals a universal relationship between the bullet hole expansion coefficient and the normalized dynamic pressure, regardless of the projectile material. However, the projectile material does affect projectile deformation, bullet hole size, and energy absorption of target.