Abstract
? 2022 Elsevier B.V.Medium entropy alloys (MEAs) strengthened by L12 ordered intermetallics have attracted extensive attention because of their unique mechanical properties that critically depend on the constituent elements. In this work, we design a CoCrNiAl3Ti3Cu6Nb0.8 MEA possessing bimodal L12 nano-precipitates to achieve improved synergy of strength and ductility. The as-prepared MEA exhibit a yield strength of 1.16 GPa, a tensile strength of 1.55 GPa, and a uniform elongation of 28%. The improved mechanical responses are attributed to the simultaneously operated strong- and weak-pair coupling effects and the hetero-deformation induced strengthening that derived from the bimodal distributed L12 nano-precipitates. The results presented herein demonstrate that bimodal distributed nano-precipitates might be a new strategy toward synergy of strength and ductility in MEAs.
NSTL
Elsevier