High Velocity Impact Testing of Intermetallic Projectiles

A high-velocity impact-ignition testing system (HITS) was developed to study the dynamic response of intermetallic projectiles impacting an inert steel target plate at speeds up to 1500 m/s. The intermetallic projectile is a binary composite of powders consolidated into a 3 g projectile contained in a 0.410 inch (10.5 mm) caliber shot gun case. The projectiles are launched from a propellant driven gun into a catch chamber equipped with view ports and imaging diagnostics. The impact events are monitored using high-speed cameras that provide local and macroscopic perspectives of fragmentation. Results demonstrate the range of visual data that can be captured including fragment count, cone angle, and velocity. A computational solid dynamics model is used to interpret the phenomenology of the experimental impact events. The model assumes an ideal case of plastic projectile and two limiting cases for the target: plastic and elastic and predicts fragmentation behavior based on brittle tension damage at lower impact velocities with increasingly severe fragmentation and smaller fragments at higher impact velocities. Results reveal that the material properties of the target have a strong influence on the trajectory of the fragments. This study provides a fundamental understanding of impact events at varied impact velocities and shows the phenomenological behavior of fragmentation.