The effect of high deformation temperatures upon the microstructural parameters of fatigued monocrystals was studied by means of transmission electron microscopy. The height and length of edge dipoles, and the mean dislocation density in the matrix bundles, were measured as functions of temperature using weak-beam contrast techniques. It was found that the mean height of the edge dipoles increased from 3.9nm at room temperature to 6.2nm at 750K. On the other hand, the dislocation density decreased with increasing temperature. This showed that the structure lengths at the microscopic scale were increased. This was the same tendency that was exhibited at the mesoscopic scale.

B.Tippelt, J.Bretschneider, C.Holste: Philosophical Magazine Letters, 1996, 74[3], 161-6