Spall strength and equation of states for 2050-T84 Al-Li alloy under shock compression up to 120 GPa

Aluminum-lithium (Al-Li) is an attractive alloy for aerospace and military applications due to its low density, excellent mechanical performance, and corrosion resistance. In this study, a series of plate-impact experiments were conducted using a powder gun and a two-stage light-gas gun to investigate the dynamic response of 2050-T84 Al-Li alloy under shock compression. The Hugoniot elastic limit, spall strength, and Hugoniot state were determined up to 120 GPa according to the measured free-surface velocity profiles and shock wave velocities. The spall strength measured for 2050-T84 Al-Li alloy was about 0.6 GPa, which is lower than that for non-lithium-bearing Al alloys due to the large grain size and different alloying compositions. The high-pressure Hugoniot data agreed well with theoretical calculations based on first-principles molecular dynamics. The dy-namic fracture and Hugoniot data obtained for 2050-T84 Al-Li alloy in the present study can guide the design of protective structures for spacecraft or artificial satellites, and lightweight aluminum alloy armor plates.