THERMODYNAMIC ANALYSIS OF DISLOCATION GLIDE CONTROLLED BY DISPERSED LOCAL OBSTACLES

The statistical-thermodynamic analysis of dislocation glide controlled by dispersed local obstacles is developed from first principles. Part 1 derives the rate equation for dislocation movement and emphasises the importance of the Gibbs free energy of activation. The components of this free energy are analysed in detail. The results are applied in Part 2 to particular types of local obstacle. It is emphasized that there are two general classes of obstacles: dispersed obstacles separate from glide dislocations and jogs in these dislocations. A thermodynamic interpretation of the experimental activation energy and activation volume is given for each class. Part 3 discusses force-distance functions as a means for relationalising experimental data. Special features of some particular functions are examined. © 1969.