Phase equilibria on the ternary Mg-Mn-Ce system at the Mg-rich corner

Three isopleths at the Mg-rich corner of Mg-Mn-Ce ternary system were investigated via thermal analysis, SEM/EPMA and XRD. A ternary eutectic reaction was observed at ∼1 wt.% Mn and 23 wt.% Ce and 592 °C. A solid-solution type ternary intermetallic compound, (Mg,Mn)12Ce, was observed with 0.5 at% solid solubility of Mn in the tetragonal Mg12Ce. With the aid of thermodynamic modeling and experiments, a revised phase diagram for the binary Mg-Ce system and the isopleths of 0.6, 1.8 and 2.5 wt.% Mn were proposed up to 25 wt.% Ce.