Radiation-induced segregation at grain boundaries of alloy 800H: Experimentally-informed atomistic simulations

The irradiation of alloys can alter the spatial distribution of solute and impurity elements. The redistribu-tion of alloying elements can cause local chemical changes at surfaces and interfaces, which may degrade the mechanical and chemical properties of alloys. In this paper, a combination of microscopic experiments and atomistic simulations are employed to study the effect of irradiation damage on radiation-induced segregation (RIS) at grain boundaries (GBs) of the alloy 800H. The grain boundary character distribution in alloy 800H was determined by electron backscatter diffraction, and proton-irradiation-induced defects were identified by transmission electron microscopy. The experimentally-observed GBs were recreated in atomistic simulations to further study their atomistic structure, grain boundary energies, and local ele-ment concentration. The effects of radiation-induced defects on the redistribution of alloying elements at various GBs were investigated. A mechanism is proposed to explain the local chemical changes at GBs after the interaction with radiation-induced dislocation loops, which is of importance to nuclear reactor performance.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

The effect of irradiation damage on radiation-induced segregation at grain boundaries of alloy 800H was studied using both microscopic experiments and atomistic simulations. The grain boundary character distribution and proton-irradiation-induced defects were determined experimentally, and recreated in atomistic simulations to study their atomistic structure and local element concentration. The impact of radiation-induced defects on the redistribution of alloying elements at various grain boundaries was investigated. A proposed mechanism explains the local chemical changes at grain boundaries after interaction with radiation-induced dislocation loops, which is significant for nuclear reactor performance.