PI: Xiao Li

Traditional recycling and manufacturing processes typically involve multiple steps, such as high-temperature melting and post-forming, which consume considerable energy. Also, the properties of recycled materials are usually degraded compared to raw materials. Solid-phase alloying is an emerging technology that provides a low-energy way to recycle/upcycle aluminum and directly extrude high-performance products. It saves energy by eliminating melting and combining consolidation, alloying, and extrusion into a single step. Furthermore, the material properties can be adjusted by tuning the chemical composition and modifying the microstructure. In this work, we use friction extrusion to upcycle AA6063 machining chips into 27 7xxx-series aluminum rods (including AA7075) with different chemical compositions by introducing different amounts of copper, zinc, and magnesium additives. After T6 heat treatment, the recycled “7075” rod achieved the same hardness and close strength as standard AA7075. The evolution of solid phase alloying was revealed by microstructure and phase identification.