1. First-principles study the effect of hydrogen atoms on the generalized stacking fault energy in γ-Fe.
- Author
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Li, Yaojun, He, Yang, Liu, Sirui, Wang, Yuexia, and Ma, Xianfeng
- Subjects
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DISLOCATIONS in metals , *HYDROGEN as fuel , *DISLOCATION nucleation , *HYDROGEN embrittlement of metals , *ATOMS - Abstract
The effect of hydrogen atoms on the generalized stacking fault energy (GSFE) of 1/6[11-2]{111} stacking fault slip system in γ-Fe is investigated using first-principles. Hydrogen atoms at two different interstitial sites on the slip plane exert opposite effects on stacking fault formation. Occupying the tetrahedral site decreases unstable GSFE from 591.61 to 519.25 mJ/m2 in pure γ-Fe, while occupancy of the octahedral site increases unstable GSFE to 733.99 mJ/m2. Hydrogen atoms not on the slip plane have minimal impact on the GSFE. As hydrogen concentration increases along [11-2] direction at the slip plane octahedral site, the GSFE curve increases significantly. Electron structure analysis reveals that the influence of hydrogen atoms on stacking faults is short-ranged, the quantity and strength of H–Fe bonds and weakened Fe–Fe bonds, govern the unstable GSFE, which provides a novel perspective to evaluate the influence of hydrogen atoms on dislocation nucleation in metals. [Display omitted] • H atom increases the stable generalized stacking fault energy of 1/6[11-2]{111} stacking fault slip system. • The H atoms occupying two different interstitial sites on the slip plane exert opposite effects of stacking fault formation. • H atom is located away from the slip plane, and the changes in generalized stacking fault energy curves are minimal. • Studied the impact of H atom concentration in different directions on generalized stacking fault energy curves. • Elucidated the mechanism of the H atom's impact on generalized stacking fault energy via H–Fe Interaction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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