High corrosion resistance and strain hardening of high Mg Al-alloy with Er and Zr by using a new reverse stabilization process

Abstract

Abstract An abnormal reverse transition of intergranular corrosion from sensitization to stabilization was observed in the Al-6.4\u202fMg-0.43Mn-0.37Er-0.17Zr alloy at low annealing temperatures between 220 and 260\u202f°C for the first time. The reverse stabilized alloy annealed at 240\u202f°C for 5\u202fh had excellent long-term corrosion resistance in the deformed state. The corresponding transmission electron microscopy analysis showed that Al 3 Mg 2 precipitates distributed separately along grain boundary, at triple junctions and the Al 6 Mn phase boundary. The combination of the low temperature reverse stabilization and retarded recrystallization by addition of Er and Zr caused the high Mg aluminum alloy to exhibit high corrosion resistance and strain hardening.