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The character of steps on gamma/alpha-2 interfaces in a low misfit lamellar TiAl-based alloy

Conference ·
OSTI ID:20001586
The defect character of steps on lamellar {gamma}/{alpha}{sub 2} interfaces in a quinternary TiAl-based alloy has been studied using high resolution transmission electron microscopy. The interfaces consisted of atomically flat coherent terraces separated by interfacial steps across equal even numbers of {l{underscore}brace}111{r{underscore}brace}{gamma} and (0002){alpha}{sub 2} planes. Circuit mapping was used to identify the Burgers vectors of these steps from lattice images obtained at [10{bar 1}]{gamma} and [{bar 1}10]{gamma} zone axes. It was found that the Burgers vectors exhibited by the two-layer steps are different from those reported previously and are consistent with those expected for perfect disconnections as described by Pond's topological theory of interfacial defects, and not with the usual partial dislocation model.
Research Organization:
Univ. of Birmingham (GB)
OSTI ID:
20001586
Report Number(s):
CONF-981104--; ISBN 1-55899-458-0; ISSN 1067-9995
Country of Publication:
United States
Language:
English