Mg-rich phase equilibria of Mg-Mn-Zn alloys analyzed by computational thermochemistry

The phase equilibria of Mg-rich Mg-Mn-Zn alloys are scrutinized on the basis of computational thermochemistry. The experimentally well-established facts are very well reproduced by the present calculation. The important invariant reaction involving Mg-solid solution is calculated to be a transition type reaction L + (Mg) <-> alpha Mn + Mg51Mn20 at 340.18 degrees C. Some aspects that were incorrectly interpreted in early experimental works are pointed out and are explained by the present calculations also involving non-equilibrium effects.