The dynamic behaviour of dislocations in intermetallics was studied by performing in situ straining experiments in a transmission electron microscope. It was found that, unlike the case at room temperature, the dislocations moved viscously at high temperatures. This was attributed to the effect of diffusive processes occurring in the dislocation cores. In the case of quasicrystals, the viscous dynamic motion could be explained in terms of processes at the cluster scale.

High-Voltage Electron Microscope High-Temperature in situ Straining Experiments to Study Dislocation Dynamics in Intermetallics and Quasicrystals. U.Messerschmidt: Journal of Microscopy, 2001, 203[1], 68-71