The ballistic performance of 99.7% alumina vis-à-vis zirconia-toughened alumina under ogive nosed projectile impact

Abstract

In this investigation, the ballistic performance of two different composites is experimentally and numerically examined under the impact of an ogive-shaped projectile with impact velocities ranging from 59 to 98 m/s. The core of these composites consists of 99.7% alumina and zirconia-toughened alumina (ZTA) ceramics, with aluminum alloy 6061-T6 sheets used to cover these two ceramic materials, forming two different types of composites. The ballistic impact tests were conducted using a pneumatic gas gun, and finite element simulations were performed using LS-DYNA^®. The experimental data were analyzed to understand residual velocity, residual kinetic energy, and dimensions of the failure zone. These findings were then compared with the results from the finite element simulations to validate the computational model. After validation, further work was focused on the failure model, crack propagation in the ceramic, and the formation of petals on the aluminum back sheet. A validated finite element model was used to compare the ballistic performance of Alumina and ZTA at higher target thickness. It was observed that the size of the fracture conoid zone increased with an increase in impact velocities, with cone angles ranging from 63° to 75°. Additionally, the ballistic limit velocity for the composite with 99.7% alumina was observed to be lower than that for the composite with zirconia toughened alumina.