Work

Understanding the Al diffusion pathway during atmospheric corrosion of a Mg-Al alloy using atom probe tomography

Year: 2025

Type: article

Abstract: Magnesium alloys continue to play a significant role in the context of lightweight structural materials, albeit that corrosion susceptibility remains a limit to their wider use. Most research to date has focused on aqueous corrosion of Mg alloys, whilst atmospheric corrosion remains poorly understood. Using atom probe tomography and a novel in-situ coating method, the native oxide layer in an additively manufactured Mg-Al alloy (AZ111) was investigated. Aluminum was found to diffuse outwards during oxidation and to be incorporated into a Mg-oxide/hydroxide rather than forming the postulated Al₂O₃ layer. This study advances the understanding of magnesium oxidation. • In-situ metal coating of APT specimens enable the analysis of the native oxide around the entire specimen of an AZ111 alloy. • Al-rich nanoclusters could be found in the LBPF produced AZ111 alloy – providing a short diffusion pathway for Al. • No evidence of the formation of an Al enriched layer (Al 2 O 3 ) at the oxide-metal interface during atmospheric corrosion. • Al incorporation was found in the surface layer of Mg hydroxide/oxide.

Source: Corrosion Science

DOI: 10.1016/j.corsci.2025.112951

Authors: Tim M. Schwarz, Nick Birbilis, Baptiste Gault, Ingrid McCarroll

Institutions: Max Planck Society, Max-Planck-Institut für Nachhaltige Materialien, Deakin University, Imperial College London

Language: English

Topic: Magnesium Alloys: Properties and Applications

Subfield: Biomaterials

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,070

Funder: Deutsche Forschungsgemeinschaft