Impact behavior and ballistic efficiency of armor-piercing projectiles with tool steel cores

Armor-piercing (AP) projectiles generally carry a hard core within a copper jacket. Upon impact on a hard target, the copper case is stripped, while the core pierces the target. The cores of the most efficient AP projectiles are built with either tungsten alloys or depleted uranium, but alloy steels are also commonly used, because they are less expensive and less polluting, even if they are much less efficient. The impact deformation and fracture behavior of armor-piercing projectiles fabricated with three different tool steel cores, and their resultant ballistic efficiency, are investigated, both to better understand the optimal mechanical properties of armor piercing materials, and to describe the impact fracture mechanics of the tested tool steels. Moreover, the ballistic results of the three tool steels are compared with those of plain medium-carbon steel and cemented tungsten carbide.