Deformation of CoCrFeNi high entropy alloy at large strain

Wang, B.*; He, H.*; Naeem, M.*; Lan, S.*; Harjo, S.   ; Kawasaki, Takuro   ; Nie, Y.*; Wang, X.-L.*; 7 of others*

The deformation behavior of an equi-atomic face-centered-cubic CoCrFeNi high entropy alloy was investigated by in-situ neutron diffraction under tensile loading up to 40% applied strain. A three-stage deformation behavior was fully captured by lattice strain and texture evolution. In spite of the chemical complexity, the deformation in CoCrFeNi is dominated by dislocation activities. Analysis of diffraction and microscopy data shows that the deformation progresses from dislocation slip to severe entanglement, where a sharp increase in dislocation density was observed. The neutron diffraction data, corroborated by transmission electron microscopy analysis, provided microscopic insights of the previously reported three-stage hardening behavior.