A model of cleavage fracture along metal/ceramic interfaces
- Univ. of California, Santa Barbara, CA (United States)
The authors propose a mechanism by which cleavage-type crack growth along a metal/ceramic interface could proceed concomitantly with significant plastic dissipation in the metal. The large strain gradients in the immediate vicinity of the crack tip are postulated to lead to extensive local hardening. A simple, continuum-based model is used to identify a characteristic length scale ahead of the crack tip, within which the material can not plastically deform subject to the crack-tip stress field. An analytical expression is derived for the crack-tip shielding afforded by the plastic zone. The coupling between the plastic dissipation and the ideal work of fracture is found to be synergistic, with slight variations in Griffith energy affecting order-of-magnitude changes in toughness. These results suggest a possible mechanism for a number of interfacial fracture phenomena observed in thick- and thin-film metal/ceramic systems, including segregation-induced interfacial embrittlement, the ductile-to-brittle transition, and stress corrosion cracking.
- OSTI ID:
- 467586
- Report Number(s):
- CONF-960401--; ISBN 1-55899-339-8
- Country of Publication:
- United States
- Language:
- English
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