Exceptional strength–ductility combination of CoCrFeMnNi high-entropy alloy with fully recrystallized structure by selective laser melting after post-deformation annealing

• DOI: 10.1016/j.jmrt.2023.01.219
• Publication Date: 2023-02-03T18:06:14Z
• Authors: Pengcheng Ji; Yandong Jia; Pan Ma; Yongkun Mu; Kang Sun; Gang Wang
• Keywords: Selective Laser Melting; Recrystallization (geology); High-Entropy Alloys; Deformation mechanism

The low yield strength of the equiatomic CoCrFeMnNi high-entropy alloy (HEA) at ambient temperature severely limits its future application as engineering materials. Here, a HEA with fully recrystallized structure and an excellent strength-ductility combination was prepared by post-deformation annealing (PDA) process (i.e., 773–1173 K for 2 h) after selective laser melting. evolution microstructures mechanical properties as-printed PDA-processed samples were systemically studied, while strengthening mechanism clarified. high density dislocations anisotropic columnar grains in improved rate stored deformation energy, thus effectively promoting grain refinement during PDA process. Compared to average size 21.26 μm sample, PDA-873 sample decreased 1.20 full recrystallization. Especially we found large amount angle boundaries (HAGBs) (∼98.3%) twin (TBs) (∼46.6%). Besides, some Cr Mn-rich oxide particles also precipitated samples. main mechanisms can be attributed boundary strengthening. exhibits strength, which is twice that samples, without sacrificing ductility significantly. present work provides effective way manipulate precipitates HEAs.