Hydrogen-induced transgranular to intergranular fracture transition in bi-crystalline nickel
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| Název: | Hydrogen-induced transgranular to intergranular fracture transition in bi-crystalline nickel |
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| Autoři: | Ding, Yu, Yu, Haiyang, PhD, 1989, Zhao, Kai, Lin, Meichao, Xiao, Senbo, Ortiz, Michael, He, Jianying, Zhang, Zhiliang |
| Zdroj: | Scripta Materialia. 204 |
| Témata: | Hydrogen embrittlement, Fracture, Grain boundary, Molecular dynamics (MD), Teknisk fysik med inriktning mot hållfasthetslära, Engineering Science with specialization in Solid Mechanics |
| Popis: | It is known that hydrogen can influence the dislocation plasticity and fracture mode transition of metallic materials, however, the nanoscale interaction mechanism between hydrogen and grain boundary largely remains illusive. By uniaxial straining of bi-crystalline Ni with a Σ5(210)[001] grain boundary, a transgranular to intergranular fracture transition facilitated by hydrogen is elucidated by atomistic modeling, and a specific hydrogen-controlled plasticity mechanism is revealed. Hydrogen is found to form a local atmosphere in the vicinity of grain boundary, which induces a local stress concentration and inhibits the subsequent stress relaxation at the grain boundary during deformation. It is this local stress concentration that promotes earlier dislocation emission, twinning evolution, and generation of more vacancies that facilitate nanovoiding. The nucleation and growth of nanovoids finally leads to intergranular fracture at the grain boundary, in contrast to the transgranular fracture of hydrogen-free sample. |
| Popis souboru: | electronic |
| Přístupová URL adresa: | https://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-451147 https://doi.org/10.1016/j.scriptamat.2021.114122 |
| Databáze: | SwePub |
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Nájsť tento článok vo Web of Science | Abstrakt: | It is known that hydrogen can influence the dislocation plasticity and fracture mode transition of metallic materials, however, the nanoscale interaction mechanism between hydrogen and grain boundary largely remains illusive. By uniaxial straining of bi-crystalline Ni with a Σ5(210)[001] grain boundary, a transgranular to intergranular fracture transition facilitated by hydrogen is elucidated by atomistic modeling, and a specific hydrogen-controlled plasticity mechanism is revealed. Hydrogen is found to form a local atmosphere in the vicinity of grain boundary, which induces a local stress concentration and inhibits the subsequent stress relaxation at the grain boundary during deformation. It is this local stress concentration that promotes earlier dislocation emission, twinning evolution, and generation of more vacancies that facilitate nanovoiding. The nucleation and growth of nanovoids finally leads to intergranular fracture at the grain boundary, in contrast to the transgranular fracture of hydrogen-free sample. |
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| ISSN: | 13596462 |
| DOI: | 10.1016/j.scriptamat.2021.114122 |