Determination of the Phase Equilibria in the Mg-Ag-Ca Ternary System at 350 °C

The phase equilibria in the Mg-Ag-Ca ternary system, in the composition range 0-35 at% Ca at 350 degrees C were investigated using 21 alloy specimens. Scanning electron microscopy equipped with an energy-dispersive spectroscope and electron probe micro-analysis were employed to analyze the constituted phases and their compositions in the alloy samples. X-ray diffraction was used to analyze the crystal structure of the constituted phases in selected samples. Four new phases named as P1, P2, P3, and P4 were found in this work. The compound P1 has a wide composition range: 52-72% Mg, 13-28% Ag, and 15-17% Ca (at.%); P2 has a narrow solid solubility: 29-33% Mg, 35-40% Ag, and 31-32% Ca (at.%) at 350 degrees C; in the present work, P4 was detected in the composition range: 12-19 at.% Mg, 59-61 at.% Ag, and 21-27 at.% Ca. In addition, the 2 theta of diffraction peaks of four new phases and nine three-phase equilibrium relationships were determined in the present work.

Automated summary

The phase equilibria in the Mg-Ag-Ca ternary system with varying Ca content were investigated, leading to the discovery of four new phases and determination of several three-phase equilibrium relationships.