Effect of pre-recovery on microstructure and properties of rolled Al-12.51Zn-2.85Mg-2.83Cu-0.18Zr-0.06Sr aluminum alloy

• Published in: Materials research express 2019-08, Vol.6 (10), p.106549
• Main Authors: Saifu, Wang, Xiaojing, Xu, Chong, Li, Chengbin, Cai, Shihao, Ju, Jindong, Huang, Chengsong, Wang, Qing, Ding
• Format: Article
• Language: English
• Subjects: corrosion resistance; high strength aluminum alloy; mechanical property; microstructure; pre-recovery
• ISSN: 2053-1591; 2053-1591
• DOI: 10.1088/2053-1591/ab38e0

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 × 1014 m−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.