Simulation of the X relaxation in FeAlMe (Me = Co, Cr, Mn, Si) alloys

We have studied the influence of alloying elements (Me) on the X relaxation in Fe–Al–C alloys, which is supposed to be due to stress-induced diffusion of the carbon atoms in the vicinity of vacancies in the D03 ordered Fe3Al. The short-range chemical interaction and long-range elastic interaction between C and Me atoms affect (1) the configuration energies of the carbon atoms, (2) the short-range order in the Fe–Al–Me–C solid solution and (3) the X relaxation, and these effects have been examined by computer simulation. It is demonstrated that Me atoms can enhance, diminish or completely suppress the X relaxation. The results of the simulation agree with the experimental findings for Co, Cr, Mn and Si as alloying elements (Me), if adequate parameters are chosen for the C–Me interaction, and are consistent with the proposed mechanism for the X relaxation.