Abstract: |
Positron annihilation spectroscopy was performed to study the microstructure of peak aged Al-Zn-Mg-Cu alloy Applying artificial ageing at different temperatures, the solute content around vacancies is found to be increased compared to as quenched state The similarity of vacancy surroundings of all artificially aged states, except for over-aged ones, suggests that peak strength is caused not only by eta' precipitates but also by GPII zones Moreover, eta' precipitates produced by artificial aging at 403 K are apparently coherent with the Al matrix (C) 2010 Acta Materialia Inc Published by Elsevier Ltd All rights reserved |