Strain Hardening and Long-Range Internal Stress in the Localized Deformation of Irradiated Polycrystalline Metals
- ORNL
Low-temperature irradiation can significantly harden metallic materials and often results in microscopic strain localization such as dislocation channeling during deformation. In true stress-true strain analyses, however, the strain localization does not significantly affect macroscopic strain-hardening behavior. It was attempted to explain the strain-hardening behavior during strain localization in terms of long-range back stresses. In theoretical modeling the long-range back stress was formulated as a function of the number of residual pileup dislocations at a grain boundary and the number of localized bands formed in a grain. The strain-hardening rates in channel deformation were calculated for ten face-centered cubic (fcc) and body-centered cubic (bcc) metals. A few residual dislocations in each channel could account for the strain-hardening rates as high as those for uniform deformation. It was also shown that the strain-hardening behavior predicted by the long-range back stress model resembled the empirical strain-hardening behaviors, which result from both localized and non-localized deformations. The predicted plastic instability stress was comparable to the tensile test data.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
- Sponsoring Organization:
- Work for Others (WFO)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1003392
- Journal Information:
- Journal of Nuclear Materials, Vol. 354, Issue 1-3; ISSN 0022-3115
- Country of Publication:
- United States
- Language:
- English
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