Experimental measurement on the phase equilibria of the Mg-Ag-Cu ternary system at 350 and 400 °C

The phase equilibria of the Mg-Ag-Cu ternary system at 350 and 400 degrees C were experimentally investigated using twenty-eight key samples. The phase equilibria and compositions in key samples were investigated using scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS). Powder X-ray diffraction (XRD) technique was used to analyze the crystal structure and solid solubility of compounds. Five three-phase equilibria and several two-phase equilibria have been determined at 350 and 400 degrees C. The solid solubility range of Cu in the compounds Mg3Ag, MgAg and fcc(Ag) were examined at 350 and 400 degrees C. The maximum solid solubility of Ag in the compound MgCu2 was found to be 11.46 at.% and 11.25 at.% with a constant value of about 66 at.% Cu at 350 and 400 degrees C, respectively. Besides, the solid solubility limits of Ag in the compounds Mg2Cu and fcc(Cu) were found to be less than 5 at.% at 350 and 400 degrees C. No ternary compound was observed in the present work. (C) 2021 Chongqing University. Publishing services provided by Elsevier B.V.