Investigation on the corrosion resistance of the Mg-10Al-xMn alloys based on thermodynamic calculations

To investigate the effect of second phase on corrosion resistance of the Mg alloys, five as-cast Mg-10Al-xMn alloys were designed based on thermodynamic calculations. The calculated phase composition and content of the alloys were confirmed by the experimental determination. The results characterized by immersed and electrochemical tests indicated the alloy 2# (PH =3.08 mm/year) has the best corrosion resistance among the five alloys. Both Gibbs energies and the content of the second phases affect the corrosion rate. A lower content of Mn in LTAl8Mn5 corresponds to a more positive Gibbs energy, which results in better corrosion resistance.

Automated summary

The corrosion resistance of alloys is influenced by both the Gibbs energies and the content of second phases, with a lower Mn content corresponding to a more positive Gibbs energy and better corrosion resistance. Alloy 2# exhibited the best corrosion resistance among the five alloys studied.