TY - JOUR
T1 - Insights into Prismatic Loop Formation in Irradiated Fe-Cr Alloys from Hypothesis-Driven Active Learning and Causal Analysis
AU - Ghosh, Saurabh
AU - Tom, Anthony
AU - Dasgupta, Dwaipayan
AU - Ghosh, Ayana
AU - Wirth, Brian D.
N1 - Publisher Copyright:
© 2024 American Chemical Society.
PY - 2024
Y1 - 2024
N2 - Neutron and electron irradiation experimental studies conducted on body-centered cubic Fe and Fe-Cr alloys have established two prismatic dislocation loop populations, which have Burgers vectors of either a/2⟨111⟩ or a⟨100⟩. The loop formation depends on factors such as dose (D), dose rate (Drt), temperature (T), chromium content (Cr%), and other alloying elements. Hence, it is important to understand how irradiation-induced dislocation loops evolve conditional upon the loop characteristics, such as loop density (DD), average loop size d̅, and irradiation parameters (D, Drt, T, and irradiation type), which is still an active area of research. To understand these complex structure-property relationships, machine learning (ML) is employed in a three-step approach. This includes imputing missing data with a k-nearest neighbor, generating functionalized features, and assessing feature importance with random forest classification and regression. Physics-based features are incorporated in a hypothesis-driven active learning scheme to overcome data unavailability challenges. Insights obtained from ML models (i) to categorize dislocation loop types, show the highest correlation with d̅; (ii) Log(DD), obtained through mathematical formulations involving D, Cr%, d̅, and T (e.g., Log(DD) ∼ D + exp(−Cr%) + 1/d̅ and log(DD) ∼ D + exp(−Cr%) + 1/T). Hypothesis-driven active learning is able to predict Log(DD) in which the experimental date is not known. Causal models verify cause-effect relationships for dislocation loop classification and irradiation factors in FeCr alloys.
AB - Neutron and electron irradiation experimental studies conducted on body-centered cubic Fe and Fe-Cr alloys have established two prismatic dislocation loop populations, which have Burgers vectors of either a/2⟨111⟩ or a⟨100⟩. The loop formation depends on factors such as dose (D), dose rate (Drt), temperature (T), chromium content (Cr%), and other alloying elements. Hence, it is important to understand how irradiation-induced dislocation loops evolve conditional upon the loop characteristics, such as loop density (DD), average loop size d̅, and irradiation parameters (D, Drt, T, and irradiation type), which is still an active area of research. To understand these complex structure-property relationships, machine learning (ML) is employed in a three-step approach. This includes imputing missing data with a k-nearest neighbor, generating functionalized features, and assessing feature importance with random forest classification and regression. Physics-based features are incorporated in a hypothesis-driven active learning scheme to overcome data unavailability challenges. Insights obtained from ML models (i) to categorize dislocation loop types, show the highest correlation with d̅; (ii) Log(DD), obtained through mathematical formulations involving D, Cr%, d̅, and T (e.g., Log(DD) ∼ D + exp(−Cr%) + 1/d̅ and log(DD) ∼ D + exp(−Cr%) + 1/T). Hypothesis-driven active learning is able to predict Log(DD) in which the experimental date is not known. Causal models verify cause-effect relationships for dislocation loop classification and irradiation factors in FeCr alloys.
KW - causal analysis
KW - dislocation loop
KW - Fe−Cr alloys
KW - fusion energy materials
KW - hypothesis-driven active learning
KW - Kr irradiation
UR - http://www.scopus.com/inward/record.url?scp=85198954757&partnerID=8YFLogxK
U2 - 10.1021/acsaem.4c00485
DO - 10.1021/acsaem.4c00485
M3 - Article
AN - SCOPUS:85198954757
SN - 2574-0962
JO - ACS Applied Energy Materials
JF - ACS Applied Energy Materials
ER -