Abstract
When cleavage nucleates from crack tips containing oxide layers or when time-dependent, subcritical crack growth occurs by a brittle cleavage or intergranular process, what is the role of an oxide film? The mechanism of stress corrosion cracking by a film rupture process has been postulated for some time. In addition, film-induced cleavage has been proposed more recently by Sieradzki and Newman. While either or both of these may exist, is there yet an even more general effect which must be considered? That is, either along with these mechanisms or in some cases in lieu of them, must we consider how oxide films affect dislocation emission which then becomes involved in shielding effects on cleavage or time-dependent failure? What we do know is that oxide films greatly affect the yield load occurring under a sharp indenter. Might this not also affect yield behavior at a crack tip since both represent sharp stress concentrators? For example, indentation induced yield excursions can vary by an order of magnitude in Fe-3wt%Si and tungsten with different oxide films. Plans for sorting this out are underway using companion experiments undergoing cleavage as well as indentation. Results on NiAl single crystals will be reported.
| Original language | English (US) |
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| Title of host publication | Cleavage Fracture |
| Editors | K.S. Chan |
| Publisher | Minerals, Metals & Materials Soc (TMS) |
| Number of pages | 1 |
| State | Published - Dec 1 1997 |
| Event | Proceedings of the 1997 TMS Fall Meeting - Indianapolis, IN, USA Duration: Sep 15 1997 → Sep 17 1997 |
Other
| Other | Proceedings of the 1997 TMS Fall Meeting |
|---|---|
| City | Indianapolis, IN, USA |
| Period | 9/15/97 → 9/17/97 |