(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: 采用透射电镜观察、硬度和电导率测试等手段研究双级时效对1973高强高韧铝合金组织和性能的影响。结果表明：一级时效温度对合金最终组织和性能的影响不大，二级时效温度和时间对1973铝合金硬度和电导率的影响明显；1973铝合金适宜的双级时效工艺为(120 ℃, 6 h)＋(160 ℃, 16 h)，在此条件下，合金的硬度和电导率分别为191HV和38.0%(IACS)，其显微组织特点为晶内沉淀相呈细小弥散状分布，而合金的晶界沉淀相粗大、呈断续状分布，并且有较明显的无沉淀析出带。合金中主要沉淀相为η'相和η相，此外还有少量的GPⅡ区。
关键字: 1973铝合金；双级时效；电导率；沉淀析出
properties of 1973 aluminum alloy
（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,
Central South University, Changsha 410083, China）
Abstract:The two-stage ageing on the microstructures and properties of 1973 aluminum alloy were studied by means of transmission electron microscopy (TEM), hardness and conductivity measurements. The results show that the temperature and time of the second-stage ageing have a key effect on the properties of the alloy, while the temperature of the first-stage ageing has little effect on them. The best two-stage ageing process for this alloy is: (120 ℃, 6 h)＋(160 ℃, 16 h). Under this condition, the hardness and electrical conductivity of this alloy are 191HV and 38.0%(IACS), respectively. The microstructure of this alloy is that the nano scale precipitates disperse inside the grain, and the coarse-discontinuous precipitates occur along the grain boundaries. The precipitated-free zones (PFZ) appear on the grain boundaries. The main precipitates are η and η' phases, and with minous GPⅡ zone.
Key words: 1973 aluminum alloy; two-stage ageing; conductivity; precipitation
