Investigation of dealloying of S phase (Al2CuMg) in AA 2024-T3 aluminium alloy using high resolution 2D and 3D electron imaging. (February 2016)

• Record Type: Journal Article
• Authors: Hashimoto, T.; Zhang, X.; Zhou, X.; Skeldon, P.; Haigh, S.J.; Thompson, G.E.
• Is Part Of: Corrosion science. Volume 103(2016)
• Page Start: 157
• Page End: 164
• Publication Date: 2016-02
• Subjects: De-alloy -- A. Aluminium -- A. Intermetallics -- B. SEM -- B. STEM -- B. TEM; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2015.11.013
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: The main body of the dealloyed S phase remnant has the same crystal structure as S phase. Copper nanoparticles are present at the intersections of remnant branches. At the surface of the remnant, a copper layer of ∼2 nm thick is present. The volume fraction of the dealloyed S phase remnant is 45–60%. Abstract: High-resolution 2D and 3D electron microscopy have been employed to investigate the dealloying of S phase (Al2 CuMg) particles in an AA 2024-T3 aluminium alloy. Preferential dissolution of magnesium and aluminium produced a sponge-like remnant with nanosize porosity and a copper-rich remnant network. The dealloyed S phase remnant retains a tetragonal structure with a smaller lattice parameter than the S phase. Metallic copper nanoparticles, constituting 4–8% of the dealloyed remnant, are present at the intersections of remnant branches. At the surface of the remnant, a copper layer of ∼2 nm thickness is formed, which terminates further dissolution of the less noble elements.