Iron chromium potential to model high-chromium ferritic alloys

Abstract

We present an Fe­Cr interatomic potential to model high-Cr ferritic alloys.The potential is fitted to thermodynamic and point-defect propertiesobtained from density functional theory (DFT) calculations and experi-ments. The developed potential is also benchmarked against otherpotentials available in literature. It shows particularly good agreementwith the DFT obtained mixing enthalpy of the random alloy, the formationenergy of intermetallics and experimental excess vibrational entropy andphase diagram. In addition, DFT calculated point-defect properties,both interstitial and substitutional, are well reproduced, as is the screwdislocation core structure. As a first validation of the potential, we studythe precipitation hardening of Fe­Cr alloys via static simulations of theinteraction between Cr precipitates and screw dislocations. It is concludedthat the description of the dislocation core modification near a precipitatemight have a significant influence on the interaction mechanisms observedin dynamic simulations.