In face-centered cubic metals, kink-pair formation in dislocation lines aligned along close-packed lattice directions could give rise to internal friction effects called Bordoni relaxation. The resulting internal friction peak was a superposition of several individual peaks, each with complex features. To study this behavior, the differential equation describing the movement of dislocation segments by thermally activated kink-pair formation was solved numerically. It was assumed that the kink mobility was high. As a result, the movement was asymmetrical, since the backward movement could occur by kink collapse without need of thermal activation. The influence of the external parameters, such as segment length, number of geometrical kinks, internal stress, amplitude and frequency of the applied stress and temperature on the position and shape of the internal friction peaks was studied. When the original configuration was in a bowed out state, the Paré condition was satisfied. Application of an external stress increased the magnitude of internal friction by aligning originally inclined dislocation segments in the direction of the Peierls valleys.

Modelling the Bordoni Peak 1. G.Schoeck: Philosophical Magazine, 2006, 86[25-26], 3819-34