Revealing the corrosion behavior of extruded Mg-4.2Y-2.2Nd-1Gd-0.6Zr alloy modified by heat treatment: A combination of experiment and first-principles calculation

Abstract

This study explored the relationship between the microstructure and corrosion behavior of Mg-4.2Y-2.2Nd-1Gd-0.6Zr alloy in different states (As-extrusion (T1), aging after extrusion (T5), and solution-aging after extrusion (T6)) using experimental methods and first-principles calculations. The results showed that fine grains and precipitates promoted uniform corrosion and formed a dense corrosion product film. Conversely, larger grains and chain-distributed block precipitates caused severe localized corrosion. The heat treatment-induced changes in alloy texture characteristics did not significantly affect the average surface energy, indicating that the current variations in texture had minimal effect on corrosion resistance.