The effect of long term creep exposure on the microstructure and properties of an underaged Al-Cu-Mg-Ag alloy

An underaged Al-Cu-Mg-Ag alloy shows zero secondary creep after 20,000 h at 130 degreesC and a stress of 200 MPa. Specimens exposed with and without an applied load reveal that dynamic precipitation of theta' and S'(S) occurs on dislocations during primary creep, whereas sigma phase forms in the matrix of the unloaded specimen. Crown Copyright (C) 2004 Published by Elsevier Ltd. on behalf of Acta Materialia Inc. All rights reserved.