Journal
ACTA MATERIALIA
Volume 53, Issue 15, Pages 4225-4235Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2005.05.022
Keywords
aluminum alloys; precipitation; coarsening; three-dimensional atom-probe tomography; creep
Ask authors/readers for more resources
Three-dimensional atom-probe tomography, transmission electron microscopy and microhardness were used to investigate the temporal evolution of nanosize, coherent Al-3(Sc1-xTix) precipitates (LI2 structure) in a coarse-grained Al-0.06at.%Sc-0.06at.%Ti alloy aged between 300 and 450 degrees C. At 300 degrees C, most scandium atoms partition within one day to the precipitates, whereas titanium atoms, even after 64 days of aging, remain predominantly in solid solution in the matrix, resulting in precipitates with average composition Al-3(Sc0.94Ti0.06). While titanium is very effective at retarding the coarsening kinetics of the precipitates, the low levels of titanium substitution result in only modest hardness increases over the binary Al-0.06at.%Sc alloy. When crept at 300 degrees C, the peak-aged alloy exhibits a threshold stress, which when normalized by the Orowan stress, increases with increasing radius, as predicted by a recent model considering elastic interactions between dislocations and coherent precipitates, and as previously observed in AI-Sc-Zr alloys. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available