Influence of Sintering Temperature on the Microstructure and Mechanical Behavior of Recycled AA2124

Aluminum and its alloys are versatile materials with inherent properties that can be enhanced through alloying. Powder metallurgy (PM) enables the production of high-strength alloys from elemental powders, which are compacted, sintered, and calibrated to the final dimensions. In this article, recycled aluminum powder is used to produce aluminum alloy 2124 via PM. The samples are compacted at 700 MPa and sintered at 550, 575, and 600 °C. Microstructural and mechanical characterizations are performed, including Thermo-Calc modeling, scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, compression, and hardness tests. The results indicate that the optimal sintering temperature for achieving maximum relative density is 550 °C, with a peak value of 98%. However, the sintering condition that exhibited the best mechanical performance and microstructural balance is 575 °C. Compared to the primary aluminum alloy, the recycled AA2124 exhibits superior relative density and enhances compressive strength, reaching an ultimate strength of 380 MPa and 33% elongation at 575 °C. This improvement is attributed to a well-balanced microstructure characterized by a refined distribution of precipitates, enhanced dispersion, and effective densification.

Influence of Sintering Temperature on the Microstructure and Mechanical Behavior of Recycled AA2124 Articles