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The interaction of dislocations and hydrogen-vacancy complexes and its importance for deformation-induced proto nano-voids formation in α-Fe

Li, Suzhi; Li, Yonggang; Lo, Yu-Chieh; Neeraj, Thirumalai; Srinivasan, Rajagopalan; Ding, Xiangdong; Sun, Jun; Qi, Liang; Gumbsch, Peter; Li, Ju

Abstract:
Abstract By using molecular dynamics and cluster dynamics simulations, we probed the role of hydrogen-vacancy complexes on nucleation and growth of proto nano-voids upon dislocation plasticity in α-Fe. Our atomistic simulations reveal that, unlike a lattice vacancy, a hydrogen-vacancy complex is not absorbed by dislocations sweeping through the lattice. Additionally, this complex has lower lattice diffusivity; therefore, it has a lower probability of encountering and being absorbed by various lattice sinks. Hence, it can exist metastably for a rather long time. Our large-scale molecular dynamics simulations show that when metals undergo plastic deformation in the presence of hydrogen at low homologous temperatures, the mechanically driven out-of-equilibrium dislocation processes can produce extremely high concentrations of hydrogen-vacancy complex (10−5 ∼ 10−3). Under such high concentrations, these complexes prefer to grow by absorbing additional vacancies and act as the embryos for the formation of proto nano-voids. The current work provides one possible route for the experimentally observed nano-void formation in hydrogen embrittlement of steels and bridges atomic-scale events and damage with macroscopic failure.



Originalveröffentlichung
DOI: 10.1016/j.ijplas.2015.05.017
Scopus
Zitationen: 50
Web of Science
Zitationen: 46
Zugehörige Institution(en) am KIT Fakultät für Maschinenbau (MACH)
Institut für Angewandte Materialien - Computational Materials Science (IAM-CMS)
Publikationstyp Zeitschriftenaufsatz
Jahr 2015
Sprache Englisch
Identifikator ISSN: 0749-6419
KITopen-ID: 1000052121
Erschienen in International Journal of Plasticity
Band 74
Seiten 175 - 191
Nachgewiesen in Scopus
Web of Science
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