Effects of solution treatment on corrosion properties of Mg6mass%Al1mass%Zn2mass%Ca (AZX612) and Mg6mass%Al1mass%Zn (AZ61) alloys

Abstract

The effects of solution treatment on the corrosion properties of Mg6 mass%Al1 mass%Zn2 mass%Ca (AZX612) alloy were investigated, and the results were compared with those for Mg6 mass%Al1 mass%Zn (AZ61) alloy. Solution treatment at 693 K for 48 h significantly reduced the corrosion rates of both AZX612 and AZ61 alloys in 5 mass% NaCl solution. After solution treatment, not only intermetallic phases but also the Al-rich ¡ phase around intermetallic phases reduced or dissolved in both alloys. The microstructural evolution induced by solution treatment may inhibit galvanic corrosion and pit-like corrosion, leading to improvement in the corrosion resistance of AZX612 and AZ61 alloys.