中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 28 No. 11 November 2018 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Science and Technology on High Strength Structural Materials Laboratory, Central South University, Changsha 410083, China）
Abstract:The microstructures and mechanical properties of Al-3.35Cu-1.2Li-0.4Mg-0.4Zn-0.3Mn-0.1Zr (mass fraction, %) alloy with Sc addition or free Sc were investigated through tensile test, SEM, EPMA and TEM. The addition of 0.082% (mass fraction) Sc element leads to the formation of Cu-rich and Sc-contained nano-sized Al3(ScZr) particles and W phase particles. The Al3(ScZr) particles can inhibit recrystallization to a certain extent and impede recrystallized grain growth during solution treatment. It is found that W phase cannot dissolve in supersaturated solid solution during the solution heat treatment, and the Cu content in the solutionized matrix is decreased, which causes a decrease in the fraction of Cu-contained strengthening precipitates with T1 (Al2CuLi) and θ'''' (Al2Cu) under T8 aging condition. Due to the formation of the W phases, the small Sc addition causes a little reduction in the strength.
Key words: Al-Li alloy; Sc addition; microstructure; mechanical properties
