<p>Among non-equilibrium processing methods, mechanical alloying is relatively simple to employ and leads to grain refinement, intermixing, solid-state interdiffusion, supersaturation beyond the equilibrium solubility limit, and chemical reactions, thereby forming metastable phases. To study the effect of Li addition in Al–Mg powders on steady-state-milling time, phase formation, high energy ball milling at different milling times was done to produce Al–5Mg (wt.%) and Al–5Mg–1.8Li (wt.%) alloy powders by using elemental powders as precursor materials and characterizations of the powders was done by X-ray diffraction (XRD), scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS), and transmission electron microscopy (TEM). According to SEM results, the milled particles exhibited a uniformly dispersed, equiaxed morphology, characteristic of the mechanical alloying process. As per XRD examination, an increasing trend in the lattice parameter up to 9 h of milling time for Al–5Mg–1.8Li and up to 6 h for Al–5Mg alloy powders shows the dissolution of Mg to Al, while a decreasing tendency indicates the completion of the Al(Mg) soluble particles/α-Al phases after 12 h and 9 h, respectively, of milling, at which point the particles reached steady-state. As indicated by XRD data, the 9 h milled Al–5Mg alloy powders completely transformed into Al(Mg) soluble particles, whereas the 12 h milled Al–5Mg–1.8Li alloy powders produced the Al₃Li phases, which are uniformly dispersed over the α-Al matrix, as confirmed by TEM analysis.</p>