Experimental investigation and thermodynamic calculation of the Mg-Mn-Ni system

Based on the critical review of the ternary Mg-Mn-Ni system, 12 alloys were prepared using a powder metallurgy method in a glove box. The isothermal section of the Mg-Mn-Ni system at 400 °C was determined. Ternary compound τ (Mg3MnNi2) was confirmed in the present work. In order to obtain the phase transition temperatures, differential scanning calorimetry (DSC) was applied to the selected alloys using sealed Ta crucibles. The invariant reaction temperatures for two invariant reactions in the Mg-rich corner were measured. Considering the experimental data from present work and literature, the Mg-Mn-Ni system was optimized and a set of thermodynamic parameters was obtained. Calculated results fit well with the experimental data.