Is. Golovin et al., EFFECT OF SUBSTITUTIONAL ORDERING ON THE CARBON SNOEK RELAXATION IN FE-AL-C ALLOYS, Physica status solidi. a, Applied research, 168(2), 1998, pp. 403-415
It is shown that the alloying of iron by Al (0 to 30 at%) shifts the c
arbon Snoek peak to a higher temperature and broadens it in the disord
ered state (quenched samples). Ageing of quenched samples with 19.6 at
% Al shifts the peak to lower temperatures and makes it more narrow du
e to substitutional ordering of the DO3-type. The explanation of conce
ntration dependence of internal friction and influence of ordering is
done on the basis of computer simulation of energy distribution for ca
rbon atoms in solid solution due to its interaction with Al atoms and
changing of this distribution due to Al ordering. The model of the lon
g-range strain-induced (elastic) C-Al interaction supplemented by the
short-range ''chemical'' interaction is successfully used. The change
of the calculated peak temperature and its width is in good agreement
with experimental data. It is shown that the main factor which determi
nes the effect of Al on the carbon Snoek peak in iron is the long-rang
e elastic interaction.