中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 23 No. 8 August 2013 |
（1. Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education),
Northeastern University, Shenyang 110004, China;
2. School of Resources and Materials, Northeastern University at Qinhuangdao, Qinhuangdao 066004, China）
Abstract:Microstructures of creep-aged 2524 (Al-4.3Cu-1.5Mg) aged at 170 °C with various stresses (0, 173 and 250 MPa) were studied on a creep machine. Ageing hardness curves under various stresses were plotted and the corresponding microstructures were characterized by transmission electron microscopy (TEM). The results show that the value of peak hardness is increased, while the time to reach the peak hardness is reduced under an external stress. Meanwhile, the length of S(Al2CuMg) phase is shorter and the number density of S phases is larger in the creep-aged alloy. The predominant contribution to the peak hardness can be ascribed to the GPB zones with an elastic stress.
Key words: creep-age; S phase; GPB zone; hardness; dislocation; stress orientation effect
