Experimental study and thermodynamic calculation of Al–Mg–Sr phase equilibria

Selected samples of ternary Al–Mg–Sr alloys were investigated using thermal analysis, scanning electron microscopy and electron microprobe analysis. Additional samples, prepared in Montreal, were re-evaluated by simulation of their X-ray diffraction spectra and by careful analysis of their thermal analysis signal curves. A comprehensive and consistent thermodynamic description for the ternary Al–Mg–Sr system is generated by assessing all experimental data from the literature combined with the present experimental results. Extended ternary solid solubilities of binary phases and one ternary intermetallic phase are established in this system. Calculated phase diagram sections and the liquidus surface together with thermodynamic equilibrium and non-equilibrium Scheil calculations of selected alloys are used to demonstrate the good agreement with all of the experimental microstructures. This provides additional support for the thermodynamic description generated in this work.