The influence of heat treatment on microstructure and mechanical response of a newly developed non-equimolar AlCrCuFeNi high-entropy alloy: Experiments and numerical modeling

Abstract

High Entropy Alloys (HEA), or more generally, Complex Concentrated Alloys (CCA) have recently shifted the manufacturing and design paradigms of metallic alloys which are more resistant and strong to mechanical loadings as well as environmental-assisted cracking. Although an extensive body of results on these special alloying systems has accrued over recent years, there are still many unknowns related to composition and microstructure and their influences on plastic deformation and failure. In this exploratory study, a new non-equimolar Multi-Principal Element Alloy along with a few annealed variant configurations is investigated by means of microstructure characterization techniques along with computational modeling. The latter is implemented to unveil the interaction of distinct mechanisms controlling the deformation process and failure in this system. For macroscopic behavior, a phenomenological approach is used to understand the plasticity and fracture under different stress states, while a mesoscale-level crystal plasticity model is carried out to determine slip system activity and its influence on plastic deformation. Overall, the new alloy exhibits rising strain hardening curves regardless of the annealing time period, but the onset of fracture is highly sensitive to heat treatment time.