Positron annihilation lifetime measurements were performed on 2 samples of this commercial alloy. One sample was deformed by 37.5% at room temperature, and was subjected to isochronal annealing at temperatures ranging from 300 to 623K. The other sample was homogenized at 823K, and was subjected to isothermal annealing at 873K. The annealing time was varied from 0 to 12h. Evidence of a non-spurious lifetime component was observed in both cases. The results for plastically deformed samples (202ps) were explained in terms of the trapping of positrons at dislocations and Li-rich zones. The results for homogenized samples (183ps) were explained only in terms of the trapping of positrons by Li-rich zones.

M.Abdelrahman: Japanese Journal of Applied Physics, 1996, 35[1-12A], 6185-7