ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The creep of uranium dioxide has been investigated as a function of grain size. At high stresses, when creep is controlled by dislocation movement, grain boundaries exert a strengthening effect and this strengthening is correlated with the Hall-Petch equation. The degree of strengthening diminishes with increases in temperature. At lower stresses, when creep is controlled by mass transport, grain boundaries exert a weakening effect owing to the reduction in diffusion path length as grain size is reduced. In this range behaviour is correlated with the Nabarro-Herring equation with stress σ replaced by an effective stressσ E=σ−σ0 whereσ 0 is a threshold stress for diffusional creep associated with the limitation of the ability of boundaries to emit and absorb vacancies.σ 0 appears to decrease as grain size is increased.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00552177
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