Internal friction of Fe-N martensite at low temperature

The internal friction behaviour of a binary Fe-N martensite is obtained by using a torsion pendulum. Results show that during heating the as-quenched martensite from 82 to 350 K three major internal friction peaks appear. Activation energies of the corresponding processes are determined to be 0.37, 0.31 and 1.26 eV, respectively. A preliminary interpretation is proposed. Dislocation relaxation processes and interactions with interstitial atoms seem to be the major reason for the internal friction behaviour.