This paper presents a correlation study between microstructure and dynamic deformation behavior of Al-Li alloys which have great potential for structural armor materials. The selected materials were a 2090 Al-Li alloy, a Weldalite 049 alloy, and a 7039 alloy, to allow a comparative study of different strengths and microstructures. These alloys were deformed at a very high strain rate by ballistic impact. The amount and the distribution of adiabatic shear bands were examined after the ballistic impact testing, and the dynamic shear stress-strain curves were obtained from the dynamic torsional Kolsky bar (shear strain rate chemical bounds approx 1200 sec~(-1)) test in order to evaluate the possibility of forming adiabatic shear bands. In the vicinity of the perforated region, adiabatic shear bands were hardly observed in the 2090 and the Weldalite alloys, whereas they easily formed in the 7039 alloy. The overall observed phenomenoloy was interpreted using the dynamic shear stress-strain curves, together with the strength level and microstructure. In the dynamic shear stress-strain curves, the maximum shear stress and the shear strain at the maximum stress point were of great importance in analyzing the adiabatic shear banding behavior, suggesting that the torsional Kolsky bar test is a good tool for evaluating the ballistic performance Al-Li alloys.
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