177 / 2023-04-15 13:32:37

High-pressure phase stability of the high-entropy alloy AlCrFeCoNi by DFT calculations

高压物理与材料科学 > 相变与机制

High entropy alloys (HEAs) often possess extraordinary mechanical properties not readily available from their constituent elemental metals or conventional alloys [1]. Nanosizing, defect formation, and secondary phase introduction are often used to further enhance the mechanical strength of HEAs. In the material processing, phase transition often occurs as a result of the complicated atomic motion and redistribution. However, whether the phase transition is driven by a change of the thermodynamic phase stability or caused by the processing dynamics is difficult to discern experimentally. In this work, we used density-functional theory calculations to study the lattice distortions and energetics of a light-weight HEA AlCrFeCoNi in the FCC, BCC and HCP structures and at pressures up to 20 GPa. Results show that in 0 – 20 GPa, the relative phase stabilities of the three phases are FCC > HCP > BCC, and among them, the BCC phase is the least compressible. These results will be combined with our experimental investigations to provide a comprehensive understanding of the structural evolution and mechanical strength of the HEA at different high-pressure processing conditions.