中文摘要：

应用慢正电子束多普勒展宽技术研究了纯Al和AA2037铝合金与腐蚀相关的缺陷.慢正电子束多普勒展宽测量是通过改变正电子的能量,测量正电子湮没的多普勒展宽谱,分析得到了不同正电子能量的S参数和S-E曲线,然后对S-E曲线进行了分析和处理以得到材料表面及近表面的缺陷真实分布.实验结果表明,纯Al与在1mol/LNaOH溶液中腐蚀引起了纳米尺度界面缺陷的产生,导致S参数明显上升;而水淬AA2037铝合金腐蚀后引起S参数明显下降,其原因可能是Cu在氧化层与基体界面富集.通过原子力显微镜（AFM）观察证实了纯Al样品表面经过腐蚀后有大量几百纳米大小的孔洞产生,而AA2037铝合金中只有少量的孔洞产生.

英文摘要：

Corrosion-related defects of pure Al and AA2037 Al alloy were investigated by measuring Doppler broadening energy spectra of positron annihilation.Defect profiles of the S parameter as a function of positron incident energy up to 30 keV were analyzed.When the sample is treated with 1 mol/L NaOH immersion for various dissolution time,a significant increase in the S parameter in pure Al is observed.This corrosion process shows the presence of defects and voids of a few nanometers near the surface.However,a significant decrease of the S parameter in water-quenched Al alloy after corrosion is observed,which is interpreted as enrichment of Cu within metal-oxide interface layer.AFM images of NaOH-dissolved samples show that there exist a lot of cavities in pure Al,but only a few cavities in Al alloy.