Precipitation in original Duralumin A-U4G versus modern 2017A alloy

• Published in: Materialia Vol. 8; p. 100429
• Main Authors: Brunet, Magali, Malard, Benoit, Ratel-Ramond, Nicolas, Deshayes, Christophe, Joulié, Sébastien, Warot-Fonrose, Bénédicte, Sciau, Philippe, Douin, Joël, De Geuser, Frédéric, Deschamps, Alexis
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2019
• Subjects: Al–Cu–Mg–Si alloy; Duralumin; Precipitation; SAXS; STEM-HAADF; Precipitation; STEM-HAADF; Duralumin; Al–Cu–Mg–Si alloy; SAXS
• ISSN: 2589-1529; 2589-1529
• DOI: 10.1016/j.mtla.2019.100429

Precipitation in Duralumin, a historic quaternary alloy of the type: Al–Cu–Mg–Si, was never fully studied nor observed by current electron microscopy techniques. This article presents the full characterization and comparison of two alloys: a Duralumin (A-U4G) from the 1950s collected on a vintage aircraft and its modern equivalent: a 2017A alloy. The as-received and peak-aging states were analysed with DSC, SAXS and TEM advanced techniques. It is shown that old Duralumin and modern 2017A present a similar nanoprecipitation in the as-received state and behave similarly upon artificial aging. As opposed to what has been reported in the past, three types of precipitates participating in hardening were found upon aging: θ’-Al2Cu, Q’(Q)-AlCuMgSi and Ω-Al2Cu.