Corrosion behavior of Mg–5Al–xZn alloys in 3.5 wt.% NaCl solution

Five types of Mg–5Al alloys with different weight percentages of Zn ranging from 0 to 4 wt.% were examined using electrochemical techniques and surface analysis. The electrochemical results indicated that the Mg–5Al alloys containing Zn have a lower corrosion and hydrogen evolution rates than the Mg–5Al based specimens with a decrease of value being observed with the decrease in Zn content. Zn addition induced the precipitation of Mg–Al and Mg–Zn phases in the Mg matrix along with grain refinement and increased an interaction of Zn oxide with Mg and Al products serving as a corrosion barrier.