Fig. 4. Phase identification and microstructure of the recycled and upcycled Al via solid-phase processing.

a XRD analysis of the recycled and upcycled Al indicated that new Mg(CuZn)₂ phases were formed in the upcycling process. b HAADF and BF images of the upcycled specimen reveal the existence of the GP zone and η′ phase nanoclusters. c Transmission electron microscopy and EDS analysis of pre-existed Mg₂Si particles reacting with newly dissolved Zn and Cu. They show potential reaction products next to pre-existing Mg₂Si particles. d 3D atom maps of Al, Zn, Mg, and Cu in the upcycled specimen. e The desorption map of the entire APT dataset with indexed crystallographic poles. f, g Sliced atom maps of Al, Zn, Mg, and Cu along the [$11\overline{1}$] pole of a selected volume with dimensions of 30 × 30 × 30 nm³.