General aspects of the corrosion of aluminium alloys

In order to understand the corrosion performance of aluminium alloys more generally, an appreciation of the chemistry and microstructure is important as the alloying elements dictate the type of microstructure that is present within the alloy - and the subsequent electrochemical response. In this work, a range of commercial alloys (aimed at capturing the range of Al-alloy series which exist) have been tested in order to give a holistic representation of the role of alloying elements in the context of corrosion. Alloying elements involved are magnesium, silicon, zinc, copper, manganese, iron, zirconium, titanium, strontium and scandium. Results are presented in the form of a 'corrosion map' of i_corr vs HVN property space - which not only typifies the trade off in properties for the range of Al-alloys but frames the challenge to push the properties towards decreased corrosion (typical of pure Al and 5xxx alloys) whilst increasing the mechanical strength.