Journal article
Fatigue Hardening and Nucleation of Persistent Slip Bands in Copper
A study of fatigue hardening in single crystals of pure copper shows that, before saturation, stress-strain loops can display workhardening rates of about a third of the elastic shear modulus. These rates exceed tensile workhardening rates by roughly two orders of magnitude. This suggests that there is a large volume fraction of obstacles to plastic flow which are essentially non-deformable and give rise to inclusion stresses of considerable magnitude.
The much lower hardening rates in cycles after saturation when persistent slip bands have formed suggest a lower volume fraction of obstacles, as is observed by transmission electron microscopy. A simple composite model involving an inclusion stress, a bowing stress and a passing, stress accounts for the workhardening rates semi-quantitatively in terms of observed dislocation microstructures.
Possible implications for polycrystals are considered.
Language: | English |
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Year: | 1982 |
Pages: | 711-718 |
ISSN: | 18780768 and 00016160 |
Types: | Journal article |
DOI: | 10.1016/0001-6160(82)90120-1 |