Positron annihilation lifetime and coincidence Doppler broadening measurements were performed on ultra low C steel and Fe-Si alloys with different Si contents (from 3.32 up to 11.1wt%) in the annealed state and after a deformation of 5% thickness reduction. It was seen that above 5.6wt%Si the nature of the defects trapping the positron changes. This coincides with the concentration for the onset of long range D03 ordering in the Fe-Si alloys changing the nature of the dislocation structure.

Defect Study of Deformed Fe-Si Alloys by Positron Annihilation Techniques. M.Agundez, D.Ruiz, S.Van Petegem, J.De Baerdemaeker, K.W.Chou, D.Segers, Y.Houbaert: Physica Status Solidi A, 2005, 202[9], 1751-7