<p>This study investigates potential alloy chemistries for the thixoforming of Mg–Al-Sr alloys in the Mg-rich region, using CALPHAD-based thermodynamic calculations to address the challenges of designing new thixoformable alloys experimentally. Given the extensive alloy space in the Mg–Al–Sr system, thermodynamic calculations were employed to model the partial isothermal section phase diagram of the Mg–Al–Sr ternary system at 450&#xa0;°C. This model was validated by comparing its predictions with literature and experimental data, showing good agreement. The thermodynamically calculated Fraction Liquid vs. Temperature (<i>f</i>_L vs. T) relationship for three alloys, Mg–4Sr–3Al, Mg–4Sr–6Al, and Mg–4Sr–9Al, was validated experimentally, with the curves closely following the Scheil–Gulliver solidification path. By varying Al and Sr concentrations systematically, the thixoforming capabilities of these alloys were assessed using parameters such as solidification interval, fraction liquid sensitivity, highest inflection point, and hot tearing susceptibility. Alloys with compositions Mg–7Al–6Sr, Mg–8Al–5Sr, and Mg–9Al–5Sr met all thixoforming design criteria. The study also distinguishes between solidification range and hot tearing susceptibility. It was found that high solidification ranges do not necessarily correlate with reduced hot tearing tendency; conversely, some alloys with shorter freezing ranges are more prone to hot tearing.</p> Graphical abstract <p></p>