中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 7 No. 1 March 1997 |
（1.Physics Department; Guangxi University; Nanning 530004 ;
2.Institute of Metals Research; Chinese Academy of Sciences; Shenyang 110015）
Abstract:The positron annihilation lifetime spectra of an Al Li Cu Mg Zr alloy in the conditions of under ageing, peak ageing and over ageing were measured. The results showed that the precipitation and growth of δ′ (Al 3Li) phase particles increased the bulk electronic density, while the precipitation of S′ (Al 2CuMg) phase particles decreased the bulk electronic density. A large number of vacancies were recovered during the peak ageing process, which made the number of defects decreased. However, the number of defects increased after the over ageing process, which was related to the precipitation of S′ phase particles.
Key words: positron lifetime spectra Al Li Cu Mg Zr alloy ageing precipitation defects bulk electronic density
