Nb Redistribution in Proton Irradiated Zrl.ONb

摘要

In this study, funded by NSUF through RTE program, microstructure and microchemistry of proton irradiated Zrl.ONb have been investigated thoroughly. Important results are listed below: 1. (S)TEM/EDS shows that irradiated Zrl.ONb contain both native precipitates and irradiation induced platelets. 2. Platelets contain up to 40 at.% Nb and have a BCC βNb crystal structure. 3. APT shows there are high density of Nb- and Fe-rich nano-clusters in the irradiated Zrl.ONb. It is hypothesized that platelets grow from those nano-clusters during irradiation. 4. Nb concentration in the Zr solid solution has been measured by APT, which shows a significant decrease of Nb solute concentration as function of irradiation dose. This result provides a strong experimental evidence to support the hypothesis that the enhanced in-reactor corrosion resistance of ZrNb alloy is due to the reduction of Nb content in Zr solid solution.