The effect of Laves phase on heavy-ion radiation response of Nb-containing FeCrAl alloy for accident-tolerant fuel cladding.

As a promising candidate material for the accident tolerant fuel cladding in light water reactors, the Nb-containing FeCrAl alloy has shown outstanding out-of-pile service performance due to the Laves phase precipitation. In this work, the radiation response in FeCrAl alloys with gradient Nb content under heavy ion radiation has been investigated. The focus is on the effect of the Laves phase on irradiation-induced defects and hardening. We found that the phase boundary between the matrix and Laves phase can play a critical role in capturing radiation defects, as verified by heavy-ion radiation experiments and molecular dynamic simulations. Additionally, the evolution of Laves phase under radiation is analyzed. Radiation-induced amorphization and segregations observed at high radiation doses will deepen the fundamental understanding of the stability of Laves phases in the radiation environment.