Enhancing the intergranular corrosion resistance of high Mg-alloyed Al-Mg alloy by Y addition

Microalloying is thought to improve the performance of Al-Mg alloys commonly used in transport applications. The effect of Y addition (0-0.4%) on the microstructure, mechanical properties, and corrosion resistance of Al-9.2Mg-0.7Mn alloy is investigated for potential use in engineering applications. The generation of the beta-Al(3)Mg(2)phase along the grain boundaries is suppressed in the as-cast alloy due to the formation of the AlMgY ternary phase. The average intergranular corrosion mass loss of the alloy with 0.1% Y addition decreases about 53.1% almost at no expense of mechanical performance in the as-rolled alloy after annealing. Moreover, the alloy with 0.1% Y addition shows the corrosion mass loss about 30.2% lower than the Y-free alloy in the sensitized state. The enhanced corrosion resistance of the alloy can be ascribed to the reduced beta-Al(3)Mg(2)precipitation along the grain boundaries associated with Y addition.