Cryogenic tensile behavior of laser additive manufactured CoCrFeMnNi high entropy alloys

Deformation Behavior of 3D‐Printed High‐Entropy Alloys: A Critical Review

“…[ 128 ] The thick cell walls trap the incoming dislocations, leading to an increase in the yield stress. [ 98 ] Notably, the disparity of dislocation density among cells also occurs, as observed in Figure a in the SLM‐fabricated AlCrFeNiV HEA. [ 137 ] This adds another dimension of microstructural heterogeneity to the 3D‐printed HEAs.…”

“…twin intersections. [98] The twin boundaries provide strengthening by decreasing the mean free path for dislocation glide. Remarkably, the intensification of twin boundaries with increasing strain provides 1) a larger capacity for gathering of dislocation and 2) routes for their further glide, thus supporting more plasticity while avoiding stress concentration.…”

“…For example, after the heat treatment of SLM‐fabricated CrMnFeCoNi alloy at 900 °C for 1 h and furnace cooling, the dislocation density decreased substantially and the cellular structure nearly vanished, as shown in Figure 1b,c. [ 97 ] Such thermodynamically metastable behavior of cellular structures can decrease the yield strength [ 98 ] and should be considered seriously in the forthcoming applications of 3D‐printed HEAs.…”

“…This results in the growth of forest dislocations, which resist external loads prominently. [ 98 ] The intercellular regions were reported to be 1–2 μm thick in the DED‐fabricated HEAs. [ 128 ] The thick cell walls trap the incoming dislocations, leading to an increase in the yield stress.…”

“…Schematic evolution of deformation features in 3D-printed HEAs: a) undeformed structure, b) dislocation glide, c) deformation twins meeting grain boundaries, d) gathering of dislocations at twin boundaries, and e) twin intersections. Reproduced with permission [98]. Copyright 2023, Elsevier.…”