DISLOCATION AND DEFECT DENSITIES BY PAT IN 2024 AIRCRAFT MATERIAL USING TWO DIFFERENT ACTIVITY SOURCES

Positron annihilation lifetime spectroscopy (PALS) is a nuclear technique used in material science. Positron annihilation lifetime technique (PALT) measurements are used to study the behavior of defect concentration and dislocation density in a set of 2024 aluminum alloy. It has been shown that positrons can become trapped at imperfect locations in solids and their mean lifetime can be influenced by changes in the concentrations of such defects. No changes were observed in the mean lifetime after defect concentration became saturated. The mean lifetime and trapping rates for the samples deformed up to 36.4 percent. The concentration of defects range from 1.133 × 1016 to 2.061 × 1018 cm-3 at strains from 1.7 to 22.7%.