Theoretical and experimental study of phase transformation and twinning behavior in metastable high-entropy alloys

Abstract

• Theoretical framework for connecting the ab initio SFEs and the prevalent deformation mechanism is established. • Critical factors affecting the deformation model transitions are identified and established. • Deformation mode map with respect to composition in Cr-Co-Ni alloys is constructed. Combined theoretical and experimental efforts are put forward to study the critical factors influencing deformation mode transitions in face-centered cubic materials. We revisit the empirical relationship between the stacking fault energy (SFE) and the prevalent deformation mechanism. With ab initio calculated SFE, we establish the critical boundaries between various deformation modes in the model Cr-Co-Ni solid solution alloys. Satisfying agreement between theoretical predictions and experimental observations are reached. Our findings shield light on applying quantum mechanical calculations in designing transformation-induced plasticity and twinning-induced plasticity mechanisms for achieving advanced mechanical properties.