( 1. 中南大学 材料科学与工程学院， 长沙 410083；
2. 邵阳学院 机械工程系， 邵阳 422004；
3. 西南铝加工厂， 重庆 401326)
摘 要: 通过力学性能检测、 扫描电镜和透射电镜观察， 研究了不同时效制度、 不同变形系数对7B04铝合金组织和性能的影响。 结果表明： 变形系数为12.5的合金其性能优于变形系数为6.5的合金； 合金的断裂属晶内韧窝断裂与沿晶断裂的混合型断裂， 合金的KC主要受其δ值的影响并与其δ值有相似的变化趋势; 合金的完全时效制度为130, 16h或140℃, 15h， 在此制度下， 合金的σb, σ0.2, δ和KC分别为645.5MPa, 603.0MPa, 11.4%和36.1MPa·m1/2。
关键字: 7B04铝合金; 时效; 组织; 性能
（ 1. School of Materials Science and Engineering,
Central South University, Changsha 410083, China;
2. Department of Mechanical Engineering,
Shaoyang Institute, Shaoyang 422004, China;
3. Southwestern Aluminum Fabrication Plant, Chongqing 401326, China）
Abstract: The effects of different ageing system and different deformation coefficient on the microstructure and mechanical properties of 7B04 aluminum alloy were investigated by means of mechanical properties test, SEM and TEM analysis.The results show that the mechanical properties of the alloy with deformation coefficient of 12.5 are higher than those of the alloy with deformation coefficient of 6.5； the fracture of the alloy is in transgranular/intergranular mixed mode and the variety of KC of the alloy resembles the variety of δ of the alloy； the complete ageing system for 7B04 alloy is 130℃, 16h or 140℃, 15h. By the ageing system, the σb, σ0.2, δ and KC of 7B04 alloy are 645.5MPa, 603.0MPa, 11.4% and 36.1MPa·m1/2， respectively.
Key words: 7B04 aluminum alloy; ageing; microstructure; properties
