Abstract
We have studied the behaviour of aluminium subjected to a low bias stress. In the temperature range of Bordoni relaxation, a thermally activated micro-deformation stage is observed and an important variation of the anelastic limit with temperature takes place. The activation parameters deduced from experimental results (about 0·2 eV and 100b3 for energy and volume respectively) are in good agreement with the Peierls-Nabarro mechanism, i.e. thermally activated double-kink formation. This hypothesis accounts for all the observed results as well as for all the essential features of the Bordoni relaxation.