(1. 中南大学 材料科学与工程学院 长沙 410083；
2. 中南大学 教育部有色金属材料科学与工程实验室，长沙 410083)
摘 要: 采用透射电子显微镜(TEM)、选区电子衍射(SADP)和硬度测试等手段研究1973高强高韧铝合金在不同温度下的单级时效析出及硬化行为。结果表明：1973铝合金在120和140 ℃有很强的抗过时效能力，峰时效过后，硬度在长时间内基本保持在195 HV附近。1973铝合金的析出序列为：α过饱和固溶体(SSS)→GPⅠ区/GPⅡ区→η'亚稳相→η平衡相→T相。在140 ℃单级时效过程中，GPⅡ区和η'相一直都存在于时效合金中，对合金起着最大的强化作用。
关键字: 1973合金；时效硬化；析出相；析出序列
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China；
2. Key laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Changsha 410083）
Abstract:The ageing precipitation and hardening behavior of 1973 high strength and high toughness aluminum alloy were studied by means of transmission electron microscopy (TEM), select area electron diffraction (SAED) and hardness measurements at different ageing temperatures. The results show that this alloy has obvious anti-over-aging capability at 120 and 140 ℃. And this alloy can keep the hardness of 195 HV in a long time after peak-ageing. Furthermore, the precipitation sequence of 1973 aluminum alloy can be described as follows: supersaturated solid solution(α)→ GPⅠ/GPⅡ zone→ metastable η'→ stable η→T phase. There are GPⅡ zone and η' phase with the greatest strengthening effect on the 1973 aluminum alloy during the whole ageing process at 140 ℃.
Key words: 1973 aluminum alloy; ageing hardening; precipitation; precipitation sequence
