Penetration Resistance of Cast Metal−Ceramic Composite Lattice Structures

Abstract

A challenging issue in armor mechanics is to optimize the impact resistance of a target per unit areal mass. Herein, the penetration resistance of an A356 alloy–ceramic lattice structure with ceramic tiles encapsulated in the metal matrix is experimentally and computationally studied to achieve this objective. A hybrid additive manufacturing/metal‐casting technique is used to fabricate the structure. The performance is experimentally evaluated by impacting the tiles at normal incidence with 0.30‐cal armor‐piercing projectiles and 7.62 M80 rounds traveling at high speed. X‐ray imaging and electron microscopy techniques are used to ascertain the quality of the castings and the damage caused to the target by the projectiles. The cast material is tested following ASTM standard E8/E8M to determine the yield stress and hardening coefficients in the Johnson–Cook model. Large deformations of the components are analyzed using the finite element software LS‐DYNA. The penetrator's computed residual velocities differ from their test values by less than 4% for the 0.30‐cal projectiles and 19% for the ball rounds. The effects of several design variables (e.g., tile thickness and location, among others) are numerically scrutinized. The proposed design is ≈20% lighter than the solid metal target to achieve the same residual velocity of the penetrator.