Penetration behaviour of a high-strength aluminium alloy

Abstract

The ballistic penetration behaviour of a high-strength aluminium alloy, 7001 T6, was investigated and targets of the alloy were found to fail in two modes, discing or plugging, depending on the orientation of the target in relation to the extrusion direction of the round bar from which it was cut. The dependence of failure mode on orientation was related to poor fracture toughness in planes containing intermetallic stringers which were aligned parallel to the extrusion direction. A model for discing failure was developed which allows the penetration resistance of the plates to be calculated from the target strength properties. It is possible to prevent both the discing and the plugging failure modes by the use of steel back-up plates in contact with the rear of the target.