(1. 常州大学 材料科学与工程学院，常州213164；
2. 常州大学 江苏省材料表面科学与技术重点实验室，常州 213164)
摘 要: 采用拉伸测试、加速腐蚀试验、扫描电镜(SEM)及透射电镜(TEM)观察，研究了120、140、160 ℃时效对固溶处理+冷轧Al-Cu-Li合金拉伸性能和晶间腐蚀(IGC)敏感性的影响。结果表明：时效过程中，合金强度和伸长率呈现先增加后减小的变化趋势；时效合金拉伸断口形貌上沿晶断裂与穿晶断裂二者并存，且随着时效时间延长，沿晶断裂比例逐渐增加；欠时效合金发生晶间腐蚀，而峰值时效及过时效合金转为孔蚀。上述变化与位错和析出特征的时效变化密切相关，且随着时效温度升高而加快。经(520 ℃, 1 h)固溶处理+60%压下量冷轧+(160 ℃, 12 h)时效处理，合金综合性能较优，抗拉强度、屈服强度和伸长率分别为582 MPa、540 MPa和4.7%，且无IGC敏感性，最大腐蚀深度约55 μm。
关键字: Al-Cu-Li合金；冷轧；时效；拉伸性能；晶间腐蚀敏感性
（1. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China;
2. Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164, China）
Abstract:The effects of ageing at 120, 140 and 160 ℃ on tensile properties and intergranular corrosion (IGC) sensitivity of the solution treated and cold rolled Al-Cu-Li alloy were investigated by tensile test, accelerating corrosion test, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that both the strength and elongation of the aged alloy first increase and then decrease during ageing process. The intergranular and transgranular fractures coexist on the fractographies of the aged alloys, and the intergranular one increases with the increase in ageing time. The underaged alloy is susceptible to IGC, whereas the peak-aged and overage alloys exhibit pitting corrosion (PC). The above change trend is related closely to the dislocations and precipitates during ageing, and furthermore becomes faster with increasing the ageing temperatures. After solution treatment (520 ℃, 1 h)+60% reduction cold rolling+artificial ageing (160 ℃, 12 h), the alloy has excellent comprehensive performance, the tensile strength, yield strength and elongation are 582 MPa, 540 MPa and 4.7%, respectively, and the alloy has low IGC sensitivity with the maximum corrosion depth of about 55 μm.
Key words: Al-Cu-Li alloy; cold rolling; ageing; tensile property; intergranular corrosion sensitivity
