An embedded-atom method potential parameterized for sulfur-induced embrittlement of nickel

D Aksoy and R Dingreville and DE Spearot, MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING, 27, 085016 (2019).

DOI: 10.1088/1361-651X/ab4c48

The embrittling or strengthening effect of solute atoms at grain boundaries (GBs), commonly known as the embrittling potency, is an essential thermodynamic property for characterizing the effects of solute segregation on GB fracture. One of the more technologically relevant material systems related to embrittlement is the Ni?S system where S has a deleterious effect on fracture behavior in polycrystalline Ni. In this work, we develop a Ni?S embedded-atom method (EAM) interatomic potential that accounts for the embrittling behavior of S at Ni GBs. Results using this new interatomic potential are then compared to previous density functional theory studies and a reactive force-field potential via a layer-by-layer segregation analysis. Our potential shows strong agreement with existing literature and performs well in predicting properties that are not included in the fitting database. Finally, we calculate embrittling potencies and segregation energies for six 100 symmetric-tilt GBs using the new EAM potential. We observe that embrittling potency is dependent on GB structure, indicating that specific GBs are more susceptible to sulfur-induced embrittlement.

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