LAUSR

Phase stability, elastic, and thermodynamic properties of (Co,Ni) 3 (Al,Mo,Nb) with the L1 2 structure have been investigated by first-principles calculations. Calculated phonon density of states show that (Co,Ni) 3 (Al,Mo,Nb) is dynamically stable, and calculated elastic constants indicate that (Co,Ni) 3 (Al,Mo,Nb) possesses intrinsic ductility. Young’s and shear moduli of the simulated polycrystalline (Co,Ni) 3 (Al,Mo,Nb) phase are calculated using the Voigt–Reuss–Hill approach and are found to be smaller than those of Co 3 (Al,W). Calculated electronic density of states depicts covalent-like bonding existing in (Co,Ni) 3 (Al,Mo,Nb). Temperature-dependent thermodynamic properties of (Co,Ni) 3 (Al,Mo,Nb) can be described satisfactorily using the Debye–Gruneisen approach, including heat capacity, entropy, enthalpy, and linear thermal expansion coefficient. Predicted heat capacity, entropy, and linear thermal expansion coefficient of (Co,Ni) 3 (Al,Mo,Nb) show significant change as a function of temperature. Furthermore the obtained data can be used in the modeling of thermodynamic and mechanical properties of Co-based alloys to enable the design of high temperature alloys.