Study of precipitates formation in Al-4.5 wt% Cu and Al-4.5 wt% Cu- 0.1 wt% In alloys using creep measurements and positron annihilation technique

Abstract

The transient and steady state creep deformation of Al-4.5 wt%Cu and Al-4.5 wt%Cu-0.1 wt%In alloys were studied using a constant stress in the aging temperatures range 403 to 703 K for various aging times under different working temperatures. Positron annihilation studies using Doppler−broadening measurements were carried out on the specimens used in creep measurements. The subsequent decrease and increase in the creep parameters n, β and εst as well as in Doppler line shape parameter with increasing aging temperatures and aging times were explained on the basis of structure transformations occurring in Al-Cu alloys. The mechanical creep measurements are very well correlated with positron annihilation characteristics.