Nanosized precipitates and dislocation networks reinforced C-containing CoCrFeNi high-entropy alloy fabricated by selective laser melting

In this paper, we report a selective laser melted C-containing CoCrFeNi high-entropy alloy (HEA) with unique cellular and columnar subgrain structures. The subgrain boundaries are made of dislocation networks decorated by the segregation of Cr element and nanosized M23C6-type carbides. Structural characterization of dislocations and dislocation reactions in dislocation networks was conducted using high-resolution transmission electron microscopy. The high strength of the C-containing HEA is attributed to dislocation networks strengthening and nanosized carbides strengthening. These findings can provide a guidance for developing HEAs with superior mechanical properties, particularly high strength.