Yield stress anomaly for {1/2}[{l{underscore}angle}112]{l{underscore}brace}111{r{underscore}brace} slip in {gamma}-titanium aluminide
Transmission electron microscopy (TEM) studies of dislocation structures in single crystals of TiAl containing 54.5 or 54.7 at% Al deformed at different temperatures revealed the occurrence of slip on {1/2}[{l{underscore}angle}112]{l{underscore}brace}111{r{underscore}brace} at room temperature and near the peak of the yield stress anomaly (YSA). Measurements of the corresponding yield stresses revealed the existence of a YSA for this type of slip. Weak-beam TEM showed the presence of locks at room temperature for 30{degree} dislocations and at high temperatures for edge dislocations. Both types of locks involve dissociation on two intersecting {l{underscore}brace}111{r{underscore}brace} type planes, driven by reduction in elastic strain energy. The edge dislocation dissociation at high temperatures involves both climb and glide.
- Research Organization:
- Univ. of Oxford (GB)
- OSTI ID:
- 20001570
- Report Number(s):
- CONF-981104-; ISBN 1-55899-458-0; ISSN 1067-9995; TRN: IM0001%%7
- Resource Relation:
- Conference: High-Temperature Ordered Intermetallic Alloys VIII, Materials Research Society Symposium Proceedings, Boston, MA (US), 11/30/1998--12/03/1998; Other Information: PBD: 1999; Related Information: In: High-temperature ordered intermetallic alloys VIII. Materials Research Society symposium proceedings: Volume 552, by George, E.P.; Mills, M.J.; Yamaguchi, Masaharu [eds.], [600] pages.
- Country of Publication:
- United States
- Language:
- English
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