1 Introduction Al–Cu–Li alloys stand out in the aerospace industry due to high modulus, high strength, and excellent fatigue resistance. They have become one of the ideal structural materials and are widely used in important structural parts such as fuselage frames and stringers [1-3]. The third-generation Al–Cu–Li alloys were characterized by an optimized balance of strength and toughness, alongside reduced anisotropy, achieved through precise control of composition and microstructure [4, 5].
