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Hot processing maps have been widely used to reveal the relationship between microstructures and final performances of Al–Li alloys after deformation. However, there are few researches on the hot processing maps of 1460 Al–Li alloy. In this paper, the safe zones were identified based on the corrected data with temperatures range from 300 to 500 °C and strain rates range from 0.001 to 10 s−1. Then, the microstructural characteristics and corresponding dynamic softening mechanisms were systematically investigated by employing various characterization methods. The optimum domains were established at 300–500 °C/0.001–0.01 s−1 dominated by continuous dynamic recrystallization and dynamic recovery, while cracks were found when temperatures set around 450 °C with the highest power dissipation efficiency value of 55%. Flow localizations and micro-shear bands were also observed in instable domains of low temperature (< 400 °C) and low strain rates (< 0.1 s−1) with lower power dissipation efficiencies (< 10%), then disappeared as temperature increased and strain rate decreased. T1 precipitate bands are developed in these micro-shear bands inside grains and provide pinning pressure on dislocation movements, impeding dynamic recovery and recrystallization processes, which is expected to be an effective way to refine grains and enhance mechanical properties. These findings can better optimize the processing parameters of this alloy and further expand its application field. [ABSTRACT FROM AUTHOR]

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 T1 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. [ABSTRACT FROM AUTHOR]

To study the effects of dynamic precipitation and processing parameters on the dynamic recrystallization (DRX) behavior of 2195 Al-Cu-Li alloy, the hot deformation process was investigated comprehensively with the temperature range of 300-500°C and strain rate range of 0.001-10 s-1. An Arrhenius-type constitutive equation and DRX kinetics model were established based on the corrected stress-strain data to unveil the relationship between processing parameters, flow stress and DRX behavior. The shape of flow curves was associated with the dynamic softening mechanism and the DRX softening fraction gradually increased with the decrease of Zener-Hollomon parameter (Z). Then, the microstructure evolution was further analyzed to elucidate the DRX mechanisms at various Z values. The primary softening mechanism was dynamic recovery (DRV). However, when temperature set between 300 and 400°C, T1 and cubic phases significantly impeded DRV and promoted the occurrence of discontinuous dynamically recrystallization (DDRX) by a strong pinning effect and considerable driving force. As Z value decreased, the recrystallization mechanism transformed from DDRX into continuous dynamic recrystallization (CDRX) attributed to the higher mobility for dislocations. Due to the reduced stored energy and the hindrance of precipitates, grain boundaries were hard to migrate, making it difficult for DDRX grains to grow continuously. [ABSTRACT FROM AUTHOR]