Single-kink relaxation processes in iron–chromium binary alloys

The internal friction spectra in cold-worked pure iron and iron–chromium alloys are measured in the inverted torsion pendulum, operating at 1.8 Hz and in the temperature range from 100 K to 600 K. The addition of chromium, in combination with a plastic deformation, activates the relaxation process producing an internal friction peak at about 210 K. The peak intensity exhibits a strong increase by increasing the concentration of solute atoms. On the basis of the estimated activation energy, E sk ∼ 0.57 eV, and atomistic simulations, this mode is assigned to the single-kink relaxation process corresponding to the recombination of geometrical kinks formed as a result of Cr-dislocation core interaction in the 1 / 2 〈 1 1 1 〉 screw dislocations.