A new interpretation of the mechanisms in Newtonian creep of uranium dioxides

摘要: Abstract Newtonian creep data on both stoichiometric and hyperstoichiometric urania materials are analyzed. It is shown that there may be two distinct regimes: one grain size sensitive, the other insensitive. Both qualitative quantitative evaluations of these regimes suggest deformation in sensitive regime controlled by lattice diffusion-accommodated boundary sliding whereas insensitive a dislocation process operating Harper-Dorn creep.