Effect of Transformation Induced Plasticity on Tensile properties of V-Cr-Fe-Co-Ni High Entropy Alloys

Abstract

This study shows a novel transformation-induced plasticity mechanism, i.e., a martensitic transformation from FCC phase to BCC phase, in high-entropy alloys (HEAs). We newly design a VCrFeCoNi HEA system in consideration of phase stability between BCC and FCC phases by thermodynamic calculations. The resultantly formed BCC martensite favorably contributes to the transformation-induced plasticity, thereby leading to a significant enhancement in strength as well as strain hardening. We reveal the microstructural evolution and phase stability varied with the Ni-Fe balance and their contributions to a mechanical response. The Ni-Fe balance plays a leading role in phase stability and consequently tunes the cryogenic-temperature strength-ductility balance. The results prove that our design approach and outstanding transformation-induced plasticity can be a novel idea in ultra-high-strength HEA design