Insight into compressive deformation mechanism of Fe2.5Ni2.5CrAl multi-principal elements alloy at elevated temperature

Due to reasonable compositions design and unique microstructure, Fe2.5Ni2.5CrAl multi-principal elements alloy (MPEA) has been demonstrated to exhibit good mechanical properties at elevated temperature. While, the deformation mechanism and dynamic behaviors have not been explored in depth. This work combined microstructure characterization and molecular dynamics (MD) simulations to address it. The compressive deformation mechanism varied with temperature. Under compressive loading, the preferred crystallographic orientations of grains changed from {001} at 200 °C to {111} at 400 °C. The dynamic recovery dominated at 400 °C, and dynamic recrystallization occurred at above 600 °C. The deformation-induced crystallographic alignment indicated a more random distribution of orientations with a decrease in texture intensity. MD simulation showed that the temperature influenced the microstructural evolution of Fe2.5Ni2.5CrAl MPEA, as well as the dislocation slip, the intrinsic stacking faults and twinning. The twin-dislocation interactions were revealed to understand the dynamic mechanical response under compression. Our study sheds light on the plastic deformation mechanisms of Fe2.5Ni2.5CrAl MPEA at elevated temperature. It provides guidance for the design and fabrication of alloys with excellent mechanical properties.