Ballistic performance of Al2O3 mosaic armors with gap-filling materials

Abstract Mosaic armors are more easily adaptable to surfaces, may have a lower cost, and maximize the preservation of their ceramic tiles after an impact. Although, the tile-to-tile interfaces are vulnerable, and the expansion of the tile that receives an impact can induce damage to the adjacent tiles. In this work, the influence of filling materials on the ballistic performance of mosaics was studied. The impedance was varied to change the intensity of transmitted stress waves on adjacent tiles. The filling materials utilized were a neat epoxy resin and a quartz-filled geopolymer and they provided stress wave transmission of 9 and 20%, respectively. Eight millimeter thick alumina tiles (99 wt% Al 2 O 3 ) were obtained from a Brazilian supplier and they were characterized. Despite the damage, there was no penetration, which suggested that the thickness and lateral dimensions of the tile were sufficient to stop the penetration of the projectile. The use of filling materials was beneficial because it prevented the expansion of the tile that received the impact, and thus, the damage to the other tiles could be reduced. Although the geopolymer-filling prevented the expansion of the tile that received the impact, it led to the detachment of the adjacent tiles. Overall, the epoxy-filled mosaics exhibited a significantly superior performance than the filling-free mosaics.