Inclined dislocation emission at a shielded crack tip
Dislocation pileup along an inclined direction from a crack tip has been observed in metals during tensile deformation in an electron microscope. Dislocations are emitted from the crack tip, move through a dislocation-free zone and pileup in the plastic zone. The problem of inclined pileup of screw dislocations at a crack tip with a dislocation free zone has been solved by applying the Wiener-Hopf method. The maximum value of K cos (psi/2), the inclined stress intensity, is used to discuss the most preferred direction of dislocation emission. The result is used to discuss the crack tip blunting versus brittle extension. It is also shown that the resistance constant K/sub g/ of dislocation emission for the material can be determined by measuring the size of the dislocation free zone.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6794708
- Report Number(s):
- CONF-840892-1; ON: DE84016703
- Country of Publication:
- United States
- Language:
- English
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