Results concerning the activation enthalpies and volumes of such obstacles were presented. Simulations revealed that, for given conditions, an obstacle field could be compared to an equidistant-obstacle arrangement. A further simplification of the activation situation could be achieved by replacing obstacle rows with a continuous obstacle wall. It was concluded that the activation volume did not always depend upon the obstacle spacing. A length-parameter was introduced which, for a real obstacle spacing, determined the number of obstacles which had to be overcome simultaneously during thermal activation. Calculations performed on obstacle fields showed that, for solute atom concentrations of between 0.1 and 20%, this length-parameter - rather than the obstacle spacing - controlled thermal activation.

Thermal Activation Analysis of Dislocations in Obstacle Fields. V.Mohles, D.Ronnpagel: Computational Materials Science, 1996, 7[1-2], 98-102