A first-principles study on D022 precipitation phases of Ni-based superalloys with loading stress and high temperature.

A first-principles study on Ni-based superalloys is performed to estimate the properties of D0 22 structure Ni 3 X (Ni 3 Nb, Ni 3 Ta, Ni 3 V) phases and L1 2 structure Ni 3 Al phase with loading stress and high temperature. By stress-strain curve, the strength is higher in D0 22 structure Ni 3 X than in L1 2 structure Ni 3 Al. Loading stress causes systems unstable to increase decomposition tendency through calculating enthalpy and E above hull. The elastic properties reflect stress decreases system modulus and increases anisotropy. The lattice misfit is affected by stress and temperature. Loading stress increases lattice misfits of D0 22 structure Ni 3 X. Raising temperature decreases lattice misfit of each system. The effect on lattice misfit is larger in stress than in temperature. Ni 3 V can form negative lattice misfit with high temperature and low stress. Through overall comparison, the D0 22 Ni 3 V has advantages on high mechanical resistance, high thermodynamic stability, excellent elastic properties, negative lattice misfit in condition of high temperature and loading stress, which can be used to develop a new precipitation strengthening Ni-based superalloy. • First-principles to evolute stabilities of D0 22 Ni 3 X with stress and temperature. • Mechanical resistance is stronger in D0 22 Ni 3 X than in L1 2 Ni 3 Al. • D0 22 Ni 3 V has advantages on thermodynamic stability and lattice misfit. [ABSTRACT FROM AUTHOR]