In-situ small angle neutron scattering analysis of hydride initiation on oxide-coated metal with surface signals enhanced by a multi-plate reaction chamber

Abstract

The surface is reacting to form layers of oxide, which lead to complex early hydriding processes prior to mass hydrogen reaction. The existence of oxide layers on top of the metal makes observation of early hydride initiation a challenging task. However, understanding of the initial hydrogen reaction mechanism of “real-life” metals is crucial for predicting the overall corrosion behaviour and properties of the material over time. To observe hydriding initiation in-situ, the small angle neutron scattering (SANS) was utilized through enhancing the signals coming from the surface structure by a special hydrogen reaction chamber. The analysis of early uranium hydriding was presented and proved traceable for deuteride precipitation. In addition, the initial deuterides were measure in-situ and in a non-destructive fashion for the first time. The deuterides were found to form when D2 consumption was accelerated (≤0.4 μmol/cm2) in uranium. The present study allowed us to analyze the initial hydrides nucleation and relate it to hydrogen consumption, thus facilitating the study on the initial hydrogen reaction mechanism.