The effect of retrogression and re-aging (RRA) treatment on the microstructural and mechanical properties of AA7012 aluminum alloy was investigated. AA7012 alloy is widely used in aerospace and automotive applications due to its high strength-to-weight ratio. The alloy was subjected to retrogression at 200°C for various durations, followed by re-aging at 160°C for different times. The evolution of the microstructure was characterized by optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Mechanical properties, including hardness, tensile strength, and yield strength, were evaluated. Results indicate that retrogression leads to partial dissolution of strengthening phases, while re-aging enhances precipitation hardening. The alloy exhibited improved mechanical properties after the RRA treatment, with optimized mechanical strength observed for a retrogression time of 5 minutes and re-aging time of 4 hours.

AA7012 Aluminum Alloy, Retrogression, Precipitation Hardening

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