预时效对8090和2091Al-Li合金中S相析出的影响
来源期刊：中南大学学报(自然科学版)1991年第6期
论文作者：郑子樵 大谷南海男
文章页码：66 - 71
关键词：Al—Li合金; S’相; 预时效; 沉淀
Key words：Al-Li alloys; S' phase; pre-aging; precipitation
摘 要：通过电镜观察,研究了190℃人工时效前的室温和150℃预时效对8090和2091Al-Li合金中S’(Al2CuMg)相析出的影响。实验结果表明,自然时效后人工时效的样品中由于空位凝聚而形成空位环,S’相在这些缺陷上优先形核长大。150℃的预时效由于增加形核驱动力而促进了S’相的析出,但影响效果不如自然时效明显。高的Cu,Mg含量有利于S’相的析出。本文讨论了S’相形成的微观机理。
Abstract: Effect of pre-aging at room temperature and 150℃ on the precipitation ofS' phase in 8090 and 2091 type Al-Li alloys was investigated by transmissionelectron microscopy, The results indicated that in the specimens naturally agedbefore aging at 190℃, S' pease was preferentially rucleated and grown on thedislocation loops formed by vacancy condensations during natural aging, Pre-aging at 150℃ promoted S' precipitation due to the increased driving forcefor precipitation. The higher Cu and Mg contents are favourable for the S'precipitation. The mechanism of S' precipitation was discussed.
