A quantitative TEM analysis of the lamellar microstructure in TiAl based alloys
- CEMES-CNRS, Toulouse (France)
- ONERA, Chatillon (France)
The microstructure of lamellar TiAl alloys was analyzed by transmission electron microscopy. Two alloys (a PST crystal and a Ti{sub 54}Al{sub 46} alloy) were investigated. The microstructure is formed by {alpha}{sub 2} and {gamma} lamellae which are very long and very thin with respect to their length. The proportion of {gamma} lamellae is higher than that of {alpha}{sub 2} lamellae. The orientation relationships associated with the {gamma}-{gamma} interfaces are examined: they correspond to the order domain, twin and pseudo-twin relationships. Statistical analyses have been performed on the volume fraction of the two phases, on the orientation of the {gamma} lamellae and on the nature of the {gamma}-{gamma} interfaces. These results are used to have a better understanding of the structural transformation (hexagonal phase - > face centered cubic phase) and the ordering process which are active in the process of formation of the microstructure during cooling.
- OSTI ID:
- 524549
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 7 Vol. 45; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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