Effect of matrix dislocation strengthening on deformation-induced martensitic transformation behavior of metastable high-entropy alloys.

In this study, we investigate the influence of dislocation strengthening in the metastable parent phase on the deformation-induced martensitic transformation behavior of a face-centered cubic (fcc) Co₂₀Cr₂₀Fe₃₄Mn₂₀Ni₆ high-entropy alloy. Annealed and hot-swaged specimens were prepared. In-situ neutron diffraction experiments captured an accelerated transformation kinetics in the hot-swaged specimen due to accumulated dislocations. The phase-specific macrostress development showed that the hexagonal close-packed $ \rvarepsilon $ ε -martensite predominantly accommodated the macroscopic plastic deformation of the annealed counterpart. Conversely, the matrix dislocation strengthening promoted cooperative plasticity of the $ \rgamma $ γ -matrix and the $ \rvarepsilon $ ε -martensitic phase, thus enhancing yield stress while preserving ductility. This paper firstly uncovers the role and significance of matrix dislocation strengthening on the mechanical behavior of metastable high-entropy alloys via in-situ neutron diffraction experiments. [ABSTRACT FROM AUTHOR]