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

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.

Automated summary

The research examined an additively manufactured aluminium alloy with high solute content, Al-14Zn-3Mg, which showed lower corrosion rate compared to a conventional wrought alloy, AA7075-T6. This difference was attributed to the microstructure and solute content of Al-14Zn-3Mg, specifically the absence of coarse intermetallic particles. Various tests were conducted to analyze the corrosion behavior of this new alloy manufactured through LPBF.