摘要
采用硬度、拉伸和剥落腐蚀测试手段,结合透射电镜和扫描电镜观察以及能谱分析,研究二次回归再时效对组织、力学和剥蚀性能的影响。二次回归再时效处理保持了类似一次回归再时效处理的晶内析出相,得到比T76过时效更粗大且离散的晶界析出相。与T76相比,二次回归再时效处理的晶界析出相具有更高的铜含量和更低的锌含量。因此,二次回归再时效处理保持了一次回归再时效处理的强度,同时得到了比T76过时效处理更高的剥蚀抗力。
Influence of dual retrogression and re-aging（dual-RRA） temper on microstructure,strength and exfoliation corrosion（EC） behavior of Al-Zn-Mg-Cu alloy was investigated by hardness measurements,tensile properties tests,exfoliation corrosion tests,transmission electron microscopy（TEM） and scanning electron microscopy（SEM） observation combined energy dispersive X-ray detector（EDX） analysis.Dual-RRA temper maintains the matrix precipitates（MPs） similar to RRA temper,meanwhile obtains coarser and sparser grain boundary precipitates（GBPs） as well as higher Cu and lower Zn content compared with T76 temper.Therefore,dual-RRA temper not only keeps strength equivalent to the RRA temper but also obtains higher EC resistance than T76 temper.
基金
Projects (2010CB731701,2012CB619502) supported by the National Basic Research Program of China
Project (50721003) supported by the Creative Research Group of National Natural Science Foundation of China
关键词
铝合金
回归再时效(RRA)
微观组织
拉伸性能
剥落腐蚀
aluminum alloy
retrogression and re-aging
microstructure
tensile properties
exfoliation corrosion
