Study of Recovery in Plastically Deformed Al-Li-Based Alloy by Positron Annihilation

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Abstract
Positron annihilation mean lifetime measurements have been performed on two samples of the commercial alloy [(8090) Al-Li-Cu-Mg-(Zr)]. One sample was deformed (37.5%) at room temperature and subjected to isochronal annealing. The temperature was varied from 300 K to 623 K. The other one was homogenized at 823 K and subjected to isothermal annealing at 873 K. The time of annealing varied from 0 to 12 h in steps of 2 h. Evidence of nonspurious lifetime component, in both cases, have been observed. The results of the plastically deformed samples (*BAR*τ*BAR* = 202±2 ps) are interpreted as trapping of positrons in dislocations and Li-rich zones. On the other hand the results of the homogenized sample (*BAR*τ*BAR* = 183±2 ps) are interpreted as trapping of positrons in Li-rich zones only.