사전 변형된 AA 2026 합금의 이중시효 열처리에 따른 석출거동 및 기계적 특성 변화

초록

This study investigates the combined effects of pre-deformation and double aging treatment on the precipitation behavior and mechanical properties of AA2026, a precipitation-strengthened Al-Cu-Mg al- loy. A 5% cold tensile strain was applied prior to aging to introduce dislocations, which served as preferential nucleation sites and enhanced solute diffusion via pipe diffusion mechanisms. The double aging treatment decouples the nucleation and growth stages through a two-step thermal cycle, enabling more precise con- trol over precipitate formation. Microstructural analysis using DSC and HR-TEM revealed that the double aging treatment led to finer and more uniformly distributed GPB zones and S′/S phases, while effectively suppressing overaging. Compared to conventional single aging, the double aging treatment significantly improved the alloy’s strength-ductility balance. These enhancements are attributed to the synergistic inter- action between dislocation-assisted nucleation and controlled thermal processing. The proposed approach offers an effective strategy to optimize the mechanical properties of AA2026 for structural applications.

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