Al3Zr nanophase-enabled anti-corrosion mechanisms in high-strength Al alloy by scalable micro-alloying design

A novel scalable approach via Zr micro-alloying to enhance the corrosion resistance of high-strength Aluminum (Al) alloy A206 without compromising mechanical strength has been proposed. The improved corrosion resistance in Zr-micro-alloyed A206 is attributed to the refined grains, narrowed precipitation-free zones (PFZs), and modified precipitates with Al 3 Zr nanophase. With these benefits, the Al 3 Zr nanophase promotes a rapid oxide passivation film, inhibits diffusion and redeposition of copper (Cu), impedes chlorine (Cl) penetration through grain boundaries (GBs), and promotes cracking tolerance to mitigate corrosion degradation. This study provides new insights into designing high-strength Al alloys with superior corrosion resistance.