THE BALLISTIC PERFORMANCE OF CONFINED AL2O3 CERAMIC TILES

The penetration of aluminum oxide tiles inserted into a 4340-steel block that also serves as a "semi-infinite" steel substrate is investigated for two length-to-diameter projectiles at a nominal impact velocity of 1.5 km s. The experimental observable is the depth of penetration of the projectile into the backup steel. These data are compared with the total penetration into semi-infinite steel. The data are analysed and displayed as normalized depth of penetration as a function of areal density and tile thickness. Data from Woolsey et al. (Fifth Annual TACOM Armor Coordinating Conference, Monterey, CAS. CA. 1989) are in good agreement with data from this study, and are used to extend the range of tile thicknesses. A methodology, assuming quasi-steady-state penetration. provides an estimate of the penetration resistance R(t) of the ceramic tile; R(t) is then used to estimate the erosion rate and length of projectile eroded as it penetrates the ceramic. A second approach that does not rely as heavily on the assumption of steady-state penetration is also developed and applied to the data to estimate the length of projectile eroded. It is found that the various measures of ceramic performance, for a well-confined target, are relatively constant as tile thickness is varied.