First-Principles Modeling of the Temperature Dependence for the Superlattice Intrinsic Stacking Fault Energies in L12 Ni75-xXxAl25 Alloys

Stronger and more resistant alloys are required in order to increase the performance and
efficiency of jet engines and gas turbines. This will eventually require planar faults engineering,
or a complete understanding of the effects of composition and temperature on the various
planar faults that arise as a result of shearing of the gamma' precipitates. In the current study, a
combined scheme consisting of the density functional theory, the quasi-harmonic Debye model,
and the axial Ising model, in conjunction with a quasistatic approach is used to assess the effects
of composition and temperature of a series of pseudo-binary alloys based on the (Ni75-xXx)Al25
system using distinct relaxation schemes to assess observed differences. Our calculations reveal
that the (111) superlattice intrinsic stacking fault energies in these systems decline modestly with
temperature between 0K and 1000 K.