Mechanical behavior of UO₂ at sub-grain length scales: A quantification of creep properties via high temperature mechanical testing

In this work, creep behavior was quantified via high temperature mechanical testing; to facilitate this, techniques were developed to: 1) measure plasticity and creep properties samples at sub-grain length scales using ex-situ mechanical testing at elevated temperatures, and 2) characterize microstructure before and after testing at the same location on the sample surface to evaluate effects of creep at the microscale. Conventional uniaxial compression testing experiments were performed under controlled atmospheres, which insured stoichiometry control, at a temperature of 900 °C, which allowed measurement of properties involving creep behavior (e.g. creep strain rates). Samples were characterized using Scanning Electron Microscopy (SEM) and Electron Backscatter Diffraction (EBSD).