The effect of time dependent native oxide surface conditions on the electrochemical corrosion resistance of Mg and Mg-Al-Ca alloys

The time dependent native oxide surface conditions of Mg and Mg-Al-Ca alloys under moderate atmospheric conditions were continuously analysed via in situ SKPFM, in situ XRR and ex situ XPS measurements. The progressive hydration of the MgO layer appears to be the dominant surface reaction for all investigated alloys during the investigated time period up to 24 h. Subsequent electrochemical measurements revealed a reduced corrosion resistance of all Mg alloys under short-term immersion conditions with a higher hydration degree of the native oxide.

Automated summary

The time dependent native oxide surface conditions of Mg and Mg-Al-Ca alloys under moderate atmospheric conditions were analyzed using in situ SKPFM, in situ XRR, and ex situ XPS measurements. The progressive hydration of the MgO layer was found to be the dominant surface reaction for all investigated alloys during the time period of up to 24 h. Subsequent electrochemical measurements showed a reduced corrosion resistance of all Mg alloys under short-term immersion conditions with a higher hydration degree of the native oxide.