Dwell and penetration of tungsten heavy alloy long-rod penetrators impacting unconfined finite-thickness silicon carbide ceramic targets

• We investigate protective properties of unconfined ceramic elements experimentally.
• Direct impact tests focus on the dwell potential of the finite-thickness ceramic.
• A bare ceramic tile can defeat a tungsten-alloy rod penetrator up to 900 m/s.
• A thin buffer layer on the ceramic shifts the threshold velocity up to 1700 m/s.
• Semi-infinite test results are confirmed for unconfined finite thickness ceramics.

Impact experiments with a tungsten heavy alloy long rod projectile against silicon carbide tiles were performed to study the transition from dwell to penetration and to compare against earlier investigations which focused either on small scale semi-infinite set-ups or on finite thickness set-ups with confinement. A depth-of-penetration configuration consisting of a ceramic tile and an extended steel backing was used to assess the impact response of the unconfined finite-thickness ceramic. The ceramic tile was either bare or had a cover plate attached to the front. The cover plate thickness has been varied and gives best results for a thickness of about half the projectile diameter used in the experiments. For the bare ceramic, a long dwell phase can be maintained up to impact velocities of around 900 m/s. For the buffered ceramic, partial dwell can be achieved up to around 1700 m/s. The results corroborate those of earlier investigations mentioned above. More importantly, the present results show that it is possible to substantially erode a heavy alloy long-rod penetrator at the surface of a finite thickness ceramic element without lateral confinement in direct impact experiments even at high impact velocities.