Quantification of the Effect of Increased Pre‐Deformation on Microstructure and Mechanical Properties of 2A55 Al–Li Alloy

Abstract

Herein, the effects of pre‐deformation to higher levels on mechanical properties, strengthening contribution, and microstructures of 2A55 Al–Li alloy are investigated. It is shown in the results that the tensile strength of 2A55 Al–Li alloy approaches 660 MPa with an elongation of 9.28% after 15% pre‐deformation. The strengthening contribution from precipitates and strain is calculated based on detailed microstructure information. The strengthening model reveals that the joint strengthening contribution of T 1 and θ ′ precipitates decreased with increasing the pre‐deformation. In contrast to the decreased strengthening contribution of precipitates in severely pre‐deformed samples, the part from pre‐deformation dramatically increases thus leading to the enhanced yield strength. It is revealed that the recovery of dislocation structure introduced by pre‐deformation is suppressed during artificial aging. Additionally, herein, the trade‐off between the strengthening contribution and elongation is presented, which can be optimized by selecting proper pre‐deformation processing.