纯铝中氢致缺陷的正电子湮没和透射电镜研究

A study of hydrogen induced defects in aluminium by PAT and TEM

用正电子湮没技术和透射电镜研究了退火和变形纯铝中的氢致缺陷。光学显微镜和透射电镜观察结果表明充氢可以在退火铝中引入气泡、位错等．纯度较低的样品比较容易形成氢致缺陷．说明铝中杂质是氢致缺陷的成核中心。正电子湮没结果表明．随着充氮量的增加．退火铝的平均正电子寿命无显著变化．变形铝的平均正电子湮没寿命有所缩短：这一结果从实验上证实了充入铝中的氢以质子形式填充于缺陷中。屏蔽了缺陷对正电子的吸引或使缺陷内的正电子寿命下降．从而降低了正电子寿命方法对缺陷的敏感性．

Hydrogen induced defects in annealed and plastically deformed pure aluminium have been studied mainly by the positron lifetime method and the transmission electron microscopy.It is revealed that the hydrogen charging can introduce blisters and dislocations in aluminium specimens.Inclusion particles in the specimens act as the nucleation sites of hydrogen induced defects. The effect of protons to shield defects from positron has been proved by the experimental results.