Modeling Bauschinger Effect Through the Reversibility of Dislocation Slip in an Al-Cu-Li Alloy

Al-Cu-Li alloys are promising lightweight materials for extensive applications in aerospace. As aerospace components often experience strain path changes during service, understanding the resulting Bauschinger effect is crucial for optimizing the fatigue resistance and performance of these alloys. This study investigates the role of T1 precipitates in the Bauschinger effect in AA2099. The presence of shearable T1 precipitates has been found to significantly influence the Bauschinger effect by reducing the strengthening effect of T1 precipitates during reverse straining. An analytical expression for slip reversibility has been derived to quantify this phenomenon, and a microstructure-based constitutive model has been developed to accurately predict the Bauschinger effect in AA2099.