Correlation between the corrosion behavior and corrosion films formed on the surfaces of Mg82-xNi18Ndx (x = 0, 5, 15) amorphous alloys

This study deals with the characterization of the corrosion films formed on the surfaces of amorphous Mg82-xNi18Ndx (x = 0, 5, 15) alloys in 3% NaCl solution saturated with Mg(OH)2. Hydrogen evolution test revealed that the addition of Nd has a beneficial effect to reduce the dissolution rate of Mg82-xNi18Ndx alloys. SEM showed that the least severe corrosion occurred for the Mg67Ni18Nd15 alloy which has the highest Nd concentration. XPS revealed that the corrosion film formed on Mg67Ni18Nd15 is the least hydroxidized among the amorphous Mg82-xNi18Ndx (x = 0, 5, 15) alloys. The improved corrosion resistance of Mg67Ni18Nd15 is attributed to the high content of oxidized Nd in the corrosion film preventing the detrimental Cl and CO32- anions from penetrating.