The glide of ordinary dislocations in the γ-phase at room temperature was studied by means of transmission electron microscopy during in situ straining. The dislocations were elongated along their screw direction, and were anchored at many pinning-points which were considered to be extrinsic to the dislocations. The dislocation glide was analyzed in detail, with special attention being paid to the unpinning process. The strength of the extrinsic obstacles was deduced from an analysis of the critical configuration at which they broke. The results were considered with the aim of balancing the contributions arising from the frictional force against the strength of the pinning-points.

An in situ Study of Ordinary Dislocation Glide in γ-TiAl Alloys. A.Couret: Philosophical Magazine A, 1999, 79[8], 1977-94