Interaction of a high-velocity steel projectile with a high-porous copper–duralumin two-layer bumper

The impact of a steel sphere 2 mm in diameter flying with a velocity of 2–7.3 km/sec on a two-layer bumper is considered. The first layer of the bumper is made of finely disperse copper powder with a density of 2.8 g/cm$^3$, and the second layer is made of Duralumin. For identical impact velocities of 3–5 km/sec and identical thicknesses and areal densities of the bumpers, the two-layer bumper leads to better failure of the steel projectile than the Duralumin bumper. In the case of the two-layer bumper used, the maximum penetration depth of fragments into the witness plate and the number of the largest craters are smaller. The order of the bumper layers does not exert any noticeable effect on projectile failure. With the impact velocity increased to 7 km/sec, the difference in shielding properties of the bumpers almost vanishes.