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MM: Fachverband Metall- und Materialphysik
MM 10: Topical Session: Hydrogen in Materials: from Storage to Embrittlement I
MM 10.2: Talk
Monday, March 18, 2024, 16:15–16:30, C 130
Strengths and Weaknesses of Classical Interatomic potentials for Hydrogen Embrittlement — •Ram Mohan Tirunelveli Vallinayagm1,2, Elena Akhmatskaya1,3, Iban Quintana2, and Mauricio Rincon Bonilla1 — 1BCAM-Basque Center for Applied Mathematics, Alameda de Mazarredo 14, E-48009 Bilbao, Spain — 2IK4-Tekniker, Surface Engineering and Materials Science Unit, Eibar, Spain — 3IKERBASQUE, Basque Foundation for Science, Plaza Euskadi 5, 48009 Bilbao, Spain
Molecular Dynamics is a common computational approach to probe the Hydrogen Embrittlement (HE) of steels at the atomistic scale. The reliability of these simulations depends on the interatomic potentials (IPs) describing particle interactions. A large number of IPs have been developed for the H-Fe system, yet no systematic benchmarking has been reported to date. Here, seven widely used IPs were benchmarked on the basis of four metrics, each critical to predicting HE: H-distribution, H-Diffusivity, Mechanical properties and H/grain boundary interactions. We put forward a classification scheme that allows practitioners to quickly choose the best IP for a particular application. The EAM potential by Song et al (Nat. Mater, 12, 145) was found to be the most adequate across the board, leading to reasonable predictions in each metric. Interestingly, we observed that other EAM IPs produce unrealistic H agglomeration, leading to long equilibration times and consistent underestimation of the H diffusivity. Poor performance of examined Modified EAM and Bond Order IPs could be due to the lack of H transport data during training.
Keywords: Interatomic Potentials; Benchmarking; Hydrogen Diffusion; Hydrogen clustering; Hydrogen embrittlement