Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 2 No. 4 November 1992|
（Central South University of Technology, Changsha 410083, China）
Abstract:The effect of double-aging on the microstructure and mechanical properties of a RS / PM A1-Li alloy has been investigated. The results show that the ductility of the alloy can be greatly improved by the treatment of prior-aging at 170℃ For 4 h and second-step aging at 190℃ for 18 h after solid solutioning. The formation of a large amount of composite precipitates (AlLi3/Al3(Li,Zr)) with suitable size, narrowing of Fσ' (Al3Li) precipitate-free zone (PFZ) at grain boundaries and more dispersive precipitation of S' (A12CuMg) phases along substructures are responsible for the improvement of the ductility of the studied alloy.
Key words: AI-Li alloy rapid solidification double-aging