|About this Abstract
||MS&T21: Materials Science & Technology
||Probing Defect Properties and Behavior under Mechanical Deformation and Extreme Conditions
||The Impact of Elastic Anisotropy on Hydride Morphology in Zirconium
||Pierre-Clement A Simon, Michael R. Tonks, Arthur T Motta, Long-Qing Chen, Mark R Daymond
|On-Site Speaker (Planned)
||Michael R. Tonks
In this work, we present new insights on the role of elastic anisotropy on hydride morphology in zirconium from a quantitative phase field model. Hydrogen in nuclear reactor fuel cladding can precipitate as a brittle hydride phase. When the nanoscale hydrides stack into circumferentially-oriented mesoscale hydrides, their impact is small. However, if they stack radially, which can occur under an applied load, they provide a preferred fracture path. Our phase field model predicts the hydride morphology observed experimentally and identifies the mechanisms responsible for nanoscale hydride stacking. The model accurately predicts experimentally-observed elongated nanoscale hydride shape and the stacking of hydrides along the basal plane of the hexagonal zirconium matrix. It also shows that an applied stress does not alter the hydride stacking within a grain. In polycrystalline structures, preferential precipitation in grains with circumferentially-aligned basal poles under applied stress appears to cause radial hydride orientation.