Autonomous Repair Mechanism of Creep Damage in Fe-Au and Fe-Au-B-N Alloys

Title

Autonomous Repair Mechanism of Creep Damage in Fe-Au and Fe-Au-B-N Alloys

 Author

Zhang, S.
Kwakernaak, C.
Tichelaar, F.D.
Sloof, W.G.
Kuzmina, M.
Herbig, M.
Raabe, D.
Brück, E.
Van der Zwaag, S.
Van Dijk, N.H.

Faculty

Applied Sciences

 Department

RST/Radiation, Science and Technology

 Date

2015-10-06

 Abstract

The autonomous repair mechanism of creep cavitation during high-temperature deformation has been investigated in Fe-Au and Fe-Au-B-N alloys. Combined electron-microscopy techniques and atom probe tomography reveal how the improved creep properties result from Au precipitation within the creep cavities, preferentially formed on grain boundaries oriented perpendicular to the applied stress. The selective precipitation of Au atoms at the free creep cavity surface results in pore filling, and thereby, autonomous repair of the creep damage. The large difference in atomic size between the Au and Fe strongly hampers the nucleation of precipitates in the matrix. As a result, the matrix acts as a reservoir for the supersaturated solute until damage occurs. Grain boundaries and dislocations are found to act as fast transport routes for solute gold from the matrix to the creep cavities. The mechanism responsible for the self-healing can be characterized by a simple model for cavity growth and cavity filling.

 To reference this document use:

http://resolver.tudelft.nl/uuid:a9eecdf0-d64a-4985-b920-4ba1768a245f

 Publisher

Springer

 ISSN

1073-5623

 Source

https://doi.org/10.1007/s11661-015-3169-9

 Source

Metallurgical and Materials Transactions A, 2015

 Part of collection

Institutional Repository

 Document type

journal article

 Rights

(c) 2015 The Author(s)
This article is published with open access at Springerlink.com
Files
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