On the corrosion of a high solute Al-Zn-Mg alloy produced by laser powder bed fusion

Highlights: • The corrosion of a high solute Al-14Zn-3Mg prepared by laser powder bed fusion (LPBF) was investigated. • The as-LPBF Al-14Zn-3Mg revealed a low corrosion rate due to the presence of fine quasicrystalline P-phase particles. • The presence of high Zn content is not detrimental to corrosion of Al-alloys. • LPBF prepared Al-14Zn-3Mg revealed a lower corrosion potential than AA7075-T6. An additively manufactured aluminium alloy with very high solute content, Al-14Zn-3Mg (wt. %), was studied herein. Compared to wrought AA7075-T6 as a benchmark, Al-14Zn-3Mg revealed a lower rate of corrosion, attributed to its microstructure and solute content. Specifically, the lack of coarse intermetallic particles in the Al-14Zn-3Mg led to reduced cathodic kinetics relative to AA7075-T6. Potentiodynamic polarisation tests and electrochemical impedance spectroscopy analysis was performed, along with XPS studies of the corresponding surface films. The findings herein demonstrate the corrosion behaviour of a new high solute aluminium alloy manufactured in net shape through LPBF.