Influence of cerium additions on the corrosion behaviour of high pressure die cast AM50 alloy

The influence of Ce additions to AM50 magnesium alloy prepared by high pressure die casting on the microstructure and corrosion behaviour has been investigated. The corrosion behaviour was evaluated by hydrogen evolution, salt spray, potentiodynamic polarization and electrochemical impedance experiments. The results show that Ce addition promotes the formation of Al11Ce3 phase and reduces the amount of β-phase (Mg17Al12). The corrosion resistance is improved with increasing Ce content which can be attributed to the formation of Al11Ce3 phase, reduction of β-phase (reduced galvanic effects) and higher purity of AME50X alloys (melt cleaning effects).

► Ce addition modified the microstructure of AM50 magnesium alloy.
► Ce addition reduces grain size of AM50 magnesium alloy.
► Ce addition causes the formation of a new phase called γ-Al11Ce3.
► The corrosion resistance is significantly increased by the addition of cerium to the AM50 alloy.