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Toughening of Brittle Materials by Dislocation Cells
Published online by Cambridge University Press: 02 July 2020
Abstract
Many attempts have been made to improve the fracture toughness of brittle materials such as ceramics. Most of the methods developed so far make use of metallurgical processes, for example, phase transformation, refining of grains, formation of composite materials. However, these methods can not be applied universally to brittle materials which do not have such a useful metallurgical processes.
Moon and Saka (1) recently showed that the fracture toughness Klc of a YAG single crystal the sub-surface of which is damaged by micro-Vickers indentation at room temperature, followed by annealing at high temperatures is improved by a factor 2 from 1.13 to 2.26MPam1/2. The fracture toughness Klc was evaluated by measuring the length of cracks which initiate at the corner of Vickers indentation(2). Transmission electron microscopy of the subsurface reveals the healing of cracks introduced by room-temperature indentation and formation of dislocation cells. The thin foil specimens were prepared using a focused ion beam (FIB) technique(3).
- Type
- Novel Microscopy Assisted Ceramic Developments in Materials Scienceand Nanotechnology (Organized by P. Gai and J. Lee)
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- Copyright
- Copyright © Microscopy Society of America 2001
References
1) Moon, W.-J., and Saka, H., Phil.Mag.Lett.,2000,80,461.Google Scholar
2) Shetty, D.K., Rosenfield, A.R., and Duckworth, W.H., 1985,J.Am.Ceram.Soc.,68,C-282.CrossRefGoogle Scholar
3) Saka, H., and Nagoya, G.,1995,Phil.Mag.Lett.,72,251.CrossRefGoogle Scholar
4) Standard samples available from JFCC.Google Scholar
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