TY - JOUR
T1 - Binding of multiple H atoms to solute atoms in bcc Fe using first principles
AU - Counts, W.
AU - Wolverton, C.
AU - Gibala, R.
N1 - Funding Information:
The authors would like to acknowledge funding from General Motors Corporation. The authors also acknowledge funding from the Department of Energy under grant DEFG36-08GO1813. The authors would like to acknowledge helpful discussions with Scott Jorgensen.
PY - 2011/8
Y1 - 2011/8
N2 - We previously performed a series of density functional theory calculations to investigate the interaction between single H atoms and point defects in body-centered cubic (bcc) Fe (Counts W, Wolverton C, Gibala R. Acta Mater 2010;58:4730). Here, we extend that work to a systematic study of binding between multiple H atoms and solute atoms in bcc Fe. We investigate the binding of multiple H atoms to one another, to interstitial C and to substitutional solutes. Our study shows the following: (i) H-H interactions are weak. The maximum attractive H-H binding energy is around 0.03 eV, which agrees with experimental values. (ii) The maximum attractive incremental binding energy of a second H atom to a C-H defect pair is 0.07 eV. (iii) We investigate the ability of 3d transition metal solutes to bind up to five H atoms. The binding energy of the second H to a 3d transition metal solute is attractive with a value ∼0.03 eV greater than binding of energy of the first, independent of solute. The binding energies of the third to fifth H atoms vary but are generally positive. Based on a stability analysis of the H binding energies, we find that the largest H-solute defect complex for V, Cr, Co, Ni and Zn contains two H atoms, while for Sc, Ti, Mn, and Cu the largest defect complex contains four H atoms.
AB - We previously performed a series of density functional theory calculations to investigate the interaction between single H atoms and point defects in body-centered cubic (bcc) Fe (Counts W, Wolverton C, Gibala R. Acta Mater 2010;58:4730). Here, we extend that work to a systematic study of binding between multiple H atoms and solute atoms in bcc Fe. We investigate the binding of multiple H atoms to one another, to interstitial C and to substitutional solutes. Our study shows the following: (i) H-H interactions are weak. The maximum attractive H-H binding energy is around 0.03 eV, which agrees with experimental values. (ii) The maximum attractive incremental binding energy of a second H atom to a C-H defect pair is 0.07 eV. (iii) We investigate the ability of 3d transition metal solutes to bind up to five H atoms. The binding energy of the second H to a 3d transition metal solute is attractive with a value ∼0.03 eV greater than binding of energy of the first, independent of solute. The binding energies of the third to fifth H atoms vary but are generally positive. Based on a stability analysis of the H binding energies, we find that the largest H-solute defect complex for V, Cr, Co, Ni and Zn contains two H atoms, while for Sc, Ti, Mn, and Cu the largest defect complex contains four H atoms.
KW - Density functional
KW - Ferritic steels
KW - Hydrogen embrittlement
KW - Iron
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U2 - 10.1016/j.actamat.2011.05.058
DO - 10.1016/j.actamat.2011.05.058
M3 - Article
AN - SCOPUS:79960409620
VL - 59
SP - 5812
EP - 5820
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
IS - 14
ER -