Department of Metals and Materials Engineering, McGill University, 3610 University Street, Montreal, Canada H3A 2B2
Abstract:
Al–Mg and Al–Mg–Zr alloys were processed by mechanical alloying. The phase constitution of the powders was strongly dependent on the composition of the starting mixture. In as-milled powders, an Al(Mg) solid solution was formed with up to 40 at% Al, which after annealing transformed to the equilibrium β-Al3Mg2 phase. For high Mg concentrations (60–90 at%) the dominant phase was γ-Al12Mg17 in accordance with the equilibrium phase diagram. The addition of Zr led to the appearance of Zr–Al intermetallics causing Mg to precipitate out of the Al(Mg) solution. The effect of zirconium was also to refine the structure and to retard grain growth.