DEFECT CONCENTRATION IN DEFORMED AlSiMgSr BY TRAPPING MODEL OF POSITRON

This paper reports the results of lifetime measurements on deformed AlSiMgSr alloy. Using the trapping model, we obtained the value of 196.7 ps for the lifetime of the free state, and 210.5 ps for the trapped state. The specific trapping rate per unit defect concentration was calculated to be 0.2280 cm2 · s-1. The concentration of defects was 5.78×1017 cm-3 when thickness reduction was 18.2%. The dislocation density for the same thickness reduction is 1.63×1010 cm-2. We have compared these values with a previously used method1 and have obtained perfect agreement for both methods, demonstrating that this a very powerful tool for detecting and evaluating defect concentration.