Annealing kinetic of quenched-in vacancies in a Fe–40 at% Al ordered alloy

It is shown that experimental results of vacancy annealing after quenching from 900 and 950°C in a Fe–40 at% Al ordered alloy are in accordance with the kinetic of nucleation and growth proposed by Damask et al. The critical size of the clusters which act as the nucleation sites for dislocation loops is determined; it corresponds to a clustering of four to six vacancies. The average binding energy vacancy–cluster is found to be between 0.15 and 0.23 eV. The vacancy elimination rate as a function of time exhibits a maximum value corresponding to the end of the nucleation stage. The migration energy is deduced for vacancies in the alloy from the investigation of the time at which the maximum occurs. The determined value of 1.61 eV is in very good agreement with those found by other classical methods.