摘要
采用硬度、电导率测试、金相及透射电镜观察等手段,研究了回归时间对7050铝合金力学和晶间腐蚀性能的影响。结果表明:合金经190℃/60min回归和再时效处理,屈服强度最高,抗晶间腐蚀能力最好,具有最佳的综合性能;但合金在接近回归硬度曲线的谷值时,经190℃/4min回归处理,抗晶间腐蚀性能最差。透射电镜观察表明,190℃回归4min时,晶界析出相粗大,基本连续分布,没有明显无沉淀析出带,4min后,随回归时间的延长,晶界无沉淀析出带略宽,同时晶界析出相逐渐粗大且不连续分布,进而提高了合金的抗晶间腐蚀性能。
The effects of retrogression time on the mechanical properties and intergranular corrosion （IGC） resistance of 7050 aluminum alloy were investigated by means of hardness and electrical conductivity test, optical microscopy （OM） and transmission electron microcopy （TEM）. The results show that the highest yield strength and IGC resistance are obtained by 190 ℃/60 rain retrogression and reaging. But when the alloy is treated near the lowest value of hardness curve of retrogression, the lowest IGC resistance is gotten by 190 ℃/4 min retrogression treatment. The TEM observation shows that the grain boundary precipitates are continuous and coarse by 190 ℃/4 min retrogression treatment, and no obvious precipitate free zone （PFZ） is observed. With retrogression time increasing, more spaced and coarser grain boundary precipitates are observed, and the PFZ becomes wider, which can attribute to improve IGC resistance of 7050 aluminum alloy.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2008年第10期1795-1801,共7页
The Chinese Journal of Nonferrous Metals
基金
国家重点基础研究发展计划资助项目(2005CB623700)
关键词
7050铝合金
回归时间
力学性能
晶间腐蚀
7050 aluminum alloy
retrogression time
mechanical properties
intergranular corrosion
