Influence of Hydrogen Absorption on Stacking Fault of Energy of a Face-Centered Cubic High Entropy Alloy

Hydrogen-induced variation of stacking fault energy (SFE) of a CrMnFeCoNi high-entropy alloy (HEA) was quantitatively evaluated by transmission electron microscopy (TEM) using weak-beam dark-field (WBDF) technique. Width of Shockley partial dislocations turned out to increase after hydrogen absorption, which indicates that hydrogen decreases the SFE of the alloy: from 31.5 ± 3.5 to 22.5 ± 2.5 mJm −2 by introduction of hydrogen into the lattice with approximate concentration of 115 wppm. This report provides the first direct observation of stacking faults under the influence of hydrogen in a face-centered cubic metallic structure. Graphical Abstract