The interfacial defect content of lamellar interfaces was studied by means of high-resolution electron microscopy, and the data were analyzed by using the topological theory of interfacial defects. It was found that the observed defects were all perfect interfacial disconnections, and that the lamellar decomposition was diffusion-controlled. Analysis of the diffusive fluxes required for disconnection motion was used to resolve a perceived discrepancy between this suggestion, and the martensitic crystallography of the TiAl lamellae. The analysis was used to explain why disconnections, with a Burgers vector of 1/3<211>, were observed in the interfaces.

Interfacial Defects and Lamellar Decomposition in Titanium Aluminides. M.Aindow, T.T.Cheng, C.Lin, H.W.Yang, P.Shang, R.C.Pond: Interface Science, 2004, 12[2-3], 293-302