LAUSR

The microstructure and mechanical properties of independently designed and manufactured Al-12.51Zn-2.85Mg-2.83Cu-0.18Zr-0.06Sr high strength aluminum alloy was investigated and the effect of pre-recovery on the alloy's performance was also studied. The results show that pre-recovery heat treatment has little effect on the alloy's crystal orientation, but it can consume deformation energy, reduce recrystallization driving force, inhibit recrystallization and decrease dislocation density ( the dislocation density decreased from 0.501 to 0.320×1014m-2). Moreover, pre-recovery heat treatment can dramatically increase the electrical conductivity of this alloy (the maximum electrical conductivity increased from 28.55% IACS to 34.01% IACS), however, the hardness all decreased after pre-recovery treatment, but the drop is very small. In addition, pre-recovery heat treatment can significantly improve the alloy's resistance to intergranular corrosion (the minimum intergranular corrosion depth decreased from 62.67?m to 47.43?m), however, the effect of pre-recovery heat treatment on the alloy's resistance to exfoliation corrosion is negligible.