Ejecta Size Resulting from Hypervelocity Impacts of Aluminum Alloy Spheres on Aluminum Alloy Targets

The effects of projectile impact velocity on ejecta fragment size were investigated by striking aluminum alloy 6061-T6 targets with 3.2-mm-diameter aluminum alloy 2017-T4 spheres at velocities ranging from 2 to 6 km/s. The two-stage light-gas gun at the Institute of Space and Astronautical Science (ISAS)/ Japan Aerospace Exploration Agency (JAXA), was used for the experiments. To examine the scattering angles of ejecta, a witness plate (150 mm × 150 mm, 2 mm in thickness) made of copper C1100P-1/4H, with a 30-mm hole in the center, was placed 50 mm in front of the target. The behavior of ejected fragments was observed using a high-speed video camera. The projected areas of ejecta collected from the test chamber after the impact experiments were measured.