High velocity impact performance of double ceramic stacking on multilayer sandwich armor structures

For a new armor system development that increases the level of ballistic protection but reduces weight, ceramic materials have recently been utilized due to their features such as low density (light-weight), high hardness, high compression strength, and high modulus of elasticity. Generally, these kinds of ceramic materials such as silicon carbide (SiC), boron carbide (B 4 C), and alumina (Al 2 O 3 ) have been used in armor systems for a while. This study aims to show the effect of using two different ceramic layers adjacent to each other and their stacking sequences on ballistic performance in multilayered ceramic/metal armor systems experimentally and analytically. Two ceramics, SiC and Alumina were used to configure the test panels in this study. For the front plate, polyurea and armor steel, and for the back plate, aluminum was arranged to form the test panels. What makes this study different is that, unlike the other studies in the literature, two ceramic layers are used adjacent to each other in all configurations. In former studies, only one or two layers of ceramic were generally used but not one just after another in stacking sequence. In addition, the extent to which the metallic front layer used in armor systems will affect the ballistic performance to protect the ceramic armor layers from external factors has been evaluated. Moreover, the optimum areal density, which was calculated as the mass per unit area, and kilogram per square meter (kg/m 2 ) of the armor configurations was obtained by keeping the same ballistic protection level to evaluate the effect of the front layer. All four configurations tested were halting the projectile successfully according to STANAG 4569 Level three ballistic test specifications. According to the test results, the configuration with the highest ballistic performance was the Config. 4 (Polyurea, SiC, Al2O3, and Aluminum) concerning with the lowest areal density. Results also showed that using ceramic layers with high hardness properties as the first layer and second layer next to it would provide better ballistic protection when compared to the ones using the ceramics separately from each other in armor solutions. In this study, the effect of the arrangement of double ceramic layers on ballistic performance in a multilayer sandwich armor system was analyzed experimentally and analytically. What makes this study different is that unlike the other studies in the literature, two ceramic layers are used adjacent to each other in all configurations. In former studies, only one or two layers of ceramic were generally used but not one just after another in stacking sequence. In addition, it has been evaluated to what extent the metallic front layer used in armor systems will affect the ballistic performance in order to protect the ceramic armor layers from external factors. On the other hand, the optimum areal density of the armor configurations was attempted to be obtained by keeping the same ballistic protection level.