Experimental study and thermodynamic modeling of the phase equilibria in the Mg-rich corner of Mg–Zn–Mn system

• Mn dissolves into MgZn2 up to 15.1 at% at 400°C, forming a ternary solid-solution compound. • Three-phase equilibria α-Mg + MgZn2 + α-Mn and liquid + α-Mg + MgZn2 are confirmed at 400°C. • CALPHAD thermodynamic modeling accurately predicts invariant reaction at 430°C, validated by DSC. • The self-consistent thermodynamic database guides compositional design of Mg–Zn–Mn alloys.