(1.中南大学材料科学与工程学院，长沙410083；
2.中南大学有色金属材料科学与工程教育部重点实验室，长沙 410083；
3.中南大学有色金属先进结构材料与制造协同创新中心，长沙 410083)
摘 要: 利用金相组织观察(OM)、扫描电镜分析(SEM)、透射电镜观察(TEM)以及硬度测试，研究固溶处理对7B04铝合金显微组织及硬度的影响。结果表明：实验合金中的η相(MgZn2)为易溶相，S相(Al2CuMg)为难溶相，含Fe杂质相为不溶相；进行单级固溶处理时，随着固溶温度的升高，实验合金的固溶程度、再结晶程度和再结晶晶粒尺寸增加，当温度超过480℃时，出现过烧现象，力学性能恶化，7B04铝合金淬火敏感性较高；双级固溶可有效抑制合金再结晶、降低合金淬火敏感性，实验条件下较好的双级固溶工艺为(450℃, 0.5h)+(490℃, 0.5h)，抑制合金再结晶效果最佳，经120℃时效24h后，硬度达到最大值，为204HV1。
关键字: 7B04铝合金；双级固溶；淬火敏感性；硬度
（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;
3.Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center, Central South University, Changsha 410083, China）
Abstract:The influence of solution treatments on the microstructure and hardness of 7B04 aluminum alloy were investigated by means of optical microscopy(OM), scanning election microscopy(SEM), transmission election microscopy(TEM) and hardness test. The results show that there are the soluble phaseη(Mg(Zn,Al,Cu)2), the poorly soluble phaseS(Al2CuMg) and the insoluble impurity Fe phase (Al7Cu2Fe). The degree of solid solution and recrystallization increases with the solution temperature increasing gradually. When the temperature exceeds 480℃, overburning on 7B04 alloy occurs and the properties was weakened, 7B04 alloy has high quench sensitivity. However, double-stage solution can inhibit recrystallization of the alloy and decrease the quench sensitivity effectively. The excellent strengthening effect can be expected at (450℃, 0.5h)+(490℃, 0.5h) among the experiments, by which the recrystallization of the alloy can be restrained mostly and the hardness can reach to 204HV1 after aging at 120℃ for 24h.
Key words: 7B04 aluminum alloy; double-stage solution; quench sensitivity; hardness
