The effect of rare earth additions on the electrochemical properties of Mg–5Al-based alloys

The corrosion properties of four Mg–5Al-based alloys with rare earth alloying elements (calcium, misch-metal and strontium) in a 0.01 M alkaline NaCl solution were examined using electrochemical tests and surface analyses. The electrochemical tests indicated that the addition of 1% rare earth improved the pitting potential, film formation and charge transfer resistance of the Mg–5Al specimens. Moreover, the addition of 1Sr produced the best corrosion resistance due to the continuous precipitation of Mg/Al-rare earth compounds as a corrosion barrier.