The relation between the shape of the stress anomaly and the structure of Fe3Al alloys

The stress anomaly for Fe3Al intermetallics exhibits various shapes in the D03 phase region. Two in situ TEM investigations at high temperatures were performed to explain this behaviour—the growth of D03 domains and the measurement of the long range order (LRO) in the D03 phase during aging. It is shown, that LRO depends on the depth under the surface of the specimen and changes during aging. In the light of this fact is possible to explain the various shape of stress anomaly.