NSUF 24-4923: Thermal stability of solute-defect clusters in structural alloys under irradiated environments

In the development of structural alloys for nuclear applications, radiation embrittlement compromises the lifespan and safety of nuclear structural components. Bombardment of energetic particles produces a non-equilibrium environment, enabling the formation of nano-size solute clusters. Understanding the formation and stability of solute clusters is critical because of their role in radiation embrittlement. However, the current understanding of solute clustering still follows the traditional concept of radiation-enhanced diffusion that accelerates diffusion kinetics, without accounting for the role of excess point defects, such as vacancies, in stabilizing solute clusters. There has been growing evidence lately suggesting that the presence of vacancies coupled with Mn-Ni-based solute clusters may provide additional thermal stability in nuclear steels compared to the defect-free solute clusters. The recent evidence and knowledge gap highlight a significant need to perform comprehensive investigation. The proposed work will investigate the thermal stability of solute clusters in reactor pressure vessel steels and Grade 91 steels under irradiated environments by a combined experimental and computational approach. The proposed work includes in situ transmission electron microscope from the Intermediate Voltage Electron Microscopy (IVEM) Facility at Argonne National Laboratory (ANL), atom probe tomography (APT) characterization at the Center for Advanced Energy Studies (CAES), as well as computational modeling at Idaho National Laboratory (INL). The central hypothesis is that the excess point defect environment created by irradiation can stabilize the formation of solute clusters, including the coupling of Mn, Ni, Si, Cu, as well as Cr and P atoms. The hypothesis will be tested by performing in situ TEM of Ne (Neon) ion irradiated alloys at the temperatures from 300°C to 800°C. The same experiments without irradiation will also be performed to isolate the role of radiation-induced excess vacancies. The thermal stability of solute clusters can be described by the critical temperature that cause complete dissolution in irradiated and non-irradiated environment. The results will be compared with the computational work at INL using the developed capability to predict the finite-temperature stability of solute clusters with excess vacancies in Fe-based steel system. The validated modeling results will serve as the benchmark that enables parameterization of multiscale models developed at INL. Successful completion of this project will enable predictive estimates of radiation-induced embrittlement at different temperatures.

추가 정보

필드	값
Award Announced Date	2024-05-28T16:54:24.347
Awarded Institution	Idaho National Laboratory
Facility Tech Lead	Alina Montrose, Kory Linton, Wei-Ying Chen, Yaqiao Wu
Irradiation Facility	Intermediate Voltage Electron Microscopy (IVEM)-Tandem Facility
PI	Jia-Hong Ke
PI Email	[email protected]
Project Type	RTE
RTE Number	None