NSUF 17-981: Quantitative assessment of the role of interfaces and grain boundaries in the development of radiation tolerant nuclear materials

Grain boundaries (GBs) are known as effective sinks for point defects created under irradiation, making them an attractive tuning parameter in order to engineer materials with superior radiation tolerance. Therefore, in the quest of advanced nuclear materials which are self-healing under irradiation and have longevity, nanocrystalline materials and GB engineering on ultrafine grain (UFG) materials have gained much traction over the past decade, however it is not clearly understood how the defects manifest and annihilate themselves at the GBs. In this user proposal, we aim to examine through in situ ion irradiation TEM experiments the role of sinks in damage mitigation at the atomic-level by understanding the interaction of irradiation induced defect clusters and dislocation loops with GBs. Specifically, we will focus on the absorption, saturation and possible ejection of these defects at sinks in GB engineered Ni alloys and nanocrystalline FCC and BCC materials (Au, Ta, Mo, and Ni). We will be primarily interested in quantifying the time dependence of defect absorption at sinks, as well as any dependence these interactions have on strain between grains; for example, the efficiency of defect absorption in UFG Ni alloys will provide results comparable to an investigation of this efficiency in more complex interfaces of nanocrystalline. The interest in time dependency of irradiation induced defect absorption makes in situ irradiation necessary for these experiments as the observation over time of defect behavior is otherwise impossible.

Additional Info

Field	Value
Abstract	Grain boundaries (GBs) are known as effective sinks for point defects created under irradiation, making them an attractive tuning parameter in order to engineer materials with superior radiation tolerance. Therefore, in the quest of advanced nuclear materials which are self-healing under irradiation and have longevity, nanocrystalline materials and GB engineering on ultrafine grain (UFG) materials have gained much traction over the past decade, however it is not clearly understood how the defects manifest and annihilate themselves at the GBs. In this user proposal, we aim to examine through in situ ion irradiation TEM experiments the role of sinks in damage mitigation at the atomic-level by understanding the interaction of irradiation induced defect clusters and dislocation loops with GBs. Specifically, we will focus on the absorption, saturation and possible ejection of these defects at sinks in GB engineered Ni alloys and nanocrystalline FCC and BCC materials (Au, Ta, Mo, and Ni). We will be primarily interested in quantifying the time dependence of defect absorption at sinks, as well as any dependence these interactions have on strain between grains; for example, the efficiency of defect absorption in UFG Ni alloys will provide results comparable to an investigation of this efficiency in more complex interfaces of nanocrystalline. The interest in time dependency of irradiation induced defect absorption makes in situ irradiation necessary for these experiments as the observation over time of defect behavior is otherwise impossible.
Award Announced Date	2017-04-26T10:15:29.853
Awarded Institution	Center for Advanced Energy Studies
Facility	Microscopy and Characterization Suite
Facility Tech Lead	Wei-Ying Chen, Yaqiao Wu
Irradiation Facility	None
PI	Mitra Taheri
PI Email	[email protected]
Project Type	RTE
RTE Number	981