(中南大学 材料科学与工程学院， 长沙 410083)
摘 要: 通过时效硬化曲线的测量、室温拉伸实验以及时效组织的电镜观察， 研究微量钪对Al-4.0Mg-1.5Cu-1.0Li-0.12Zr合金时效行为、显微组织和力学性能的影响。 结果表明： 微量钪的添加能显著增强该合金的时效硬化和强化效果。 微观组织分析发现， 微量钪的添加可促进Al3Li/Al3(Sc, Zr)复合相与δ′相的弥散析出。 通过对合金时效过程中析出相的分析， 发现在所研究的合金中析出了Z相， 表明微量银不是Z相析出的必要条件。
关键字: 铝锂合金； 微观结构； 微合金化； 钪
（School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: The microstructural evolution and ageing behaviour of Al-4.0Mg-1.5Cu-1.0Li-(0.2Sc)-0.12Zr alloys were investigated. The results indicate that trace of Sc can modify the ageing characteristics of Al-4.0Mg-1.5Cu-1.0Li-0.12Zr alloys; the higher peak hardness and strength can be achieved. TEM observations show that the small addition of Sc can stimulate the precipitation of Al3Li/Al3(Sc, Zr) compound particles and δ′ in the Sc-containing alloy. Z phase can be precipitated in both Sc-free and Sc-containing Al-4.0Mg-1.5Cu-1.0Li-0.12Zr alloys, and it seems that small addition of silver is not the necessary condition for the precipitation of Z phase.
Key words: aluminium-lithium alloy; microstructure; microalloying; Sc
