Effect of Re on mechanical properties of single crystal Ni-based superalloys: Insights from first-principle and molecular dynamics

Re is one of the newly added key elements of single crystal Ni-based superalloys for advanced aero-engine turbine blades. The mechanisms that how Re influences the mechanical behavior of single crystal Ni-based superalloys are still debatable. In the present work, we trace back to some Re associated fundamental aspects affecting mechanical behavior by experiments, first-principle and molecular dynamics methods. The distribution of Re, the effect of Re on lattice parameter, stacking fault energy, elastic and plastic deformations at different temperatures are systematically analyzed. The results not only quantitatively reveal some significant mechanisms behind the Re effect, but also bring inputs for larger scale simulation methods. Based on the simulation results, the influence of Re on long-term deformation property of single crystal Ni-based superalloys is reasonably discussed in the viewpoint of thermodynamic and dislocation dynamics.