Thermodynamic assessment of Al–Cu–Dy system

Phase equilibria of ternary Al–Cu–Dy system has been analyzed and a complete thermodynamic description was obtained. The thermodynamic descriptions of its three constituent binary systems were taken from literature. Most of the binary intermetallic phases, except Al2Dy, Cu2Dy, and CuDy, were treated to have zero solubility in ternary system. Based on experimental data, seven stable ternary intermetallic phases were taken into consideration in this system. Among them, three were treated as semistoichiometric compounds with large homogeneity ranges for Al and Cu. The rest were treated as stoichiometric compounds. The calculated phase equilibria were in agreement with available experimental data.