ISSN:
1059-910X
Keywords:
TEM
;
Morphology
;
Crystallography
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Natural Sciences in General
Notes:
The distribution, morphology, chemistry, and crystallography of the precipitates formed during aging of an Al-Cu-Zn-Mg-Ag alloy have been studied using analytical transmission electron microscopy. The first precipitates to appear during aging at 150°C were thin hexagonal-shaped plate-like precipitates which formed on the {111}Al planes. These precipitates had a face-centred orthorhombic crystal structure and their composition was essentially CuAl2 although they contained a trace of silver. At peak hardness the microstructure consisted of the plate-like precipitates on {111}Al planes and θ′ precipitates on {100}Al planes. Overaging resulted in the precipitation of equilibrium θ, CuAl2, which exhibited a lath morphology and an orientation-relationship with the matrix (210)Al ∥(110)γ; (001)Al misorlented from (001)γ by ∼6°. Prolonged overaging at 250°C resulted in the formation of cuboid-shaped Al5(Cu,Zn)6Mg2 precipitates which had a cubic crystal structure and a cube:cube orientation-relationship with the matrix. © 1993 Wiley-Liss, Inc.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jemt.1070240409
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