微量Ag和Mg在2195合金中的合金化作用

来源期刊：中南大学学报(自然科学版)1998年第1期

论文作者：郑子樵 黄碧萍 尹登峰

文章页码：42 - 45

关键词：铝合金;锂合金;银;合金化;析出过程;拉伸性能

Key words：Al alloy; Li alloy; Ag; alloying; precipitation; tensile propertie

摘    要：通过力学性能试验和显微组织观察研究了2195合金中微量Ag和Mg的合金化作用.结果表明,在2195合金中由于Ag和Mg的添加使T1相的析出速度加快,析出密度增加,并以T1相为主要强化相,时效强化效果最大.只含Mg的合金在时效时析出GP区,θ′和T1相,θ′相为主要时效强化相.只含Ag的合金在峰时效时析出粗大的T1和θ′相,强化效果较小.由于铃木效应促使Ag和Mg原子在{111}α面上的层错中偏聚以及Ag-Mg clusters对Li和Cu原子扩散的催化作用为T1相形核提供了结构和成份条件.

Abstract: The alloying role of Ag and Mg elements in 2195 alloy has been studied by tensile testing and transmission electron microscopy.The results indicate that the addition of Ag and Mg in 2195 alloy will accelarate T1precipitation and result in increasing density of T1precipitates.The higher strength of 2195 alloy is attributed to high volume fractions of T1phase.For the Ag-free 2195 alloy GP zones are formed at the early aging stage,θ′and T1phases precipitate with increased aging time. The Ag-free 2195 alloy is strengthened byθ′phase mainly in the peak aging.In the Mg-free 2195 alloy the coarse T1andθ′phases precipitate during the peak aging,which results in the lower strength.Ag and Mg atoms are supposed to be segregate to the stacking faults on the {111}αplanes to form Ag-Mg clusters due to the strong Ag-Mg interaction.These clusters may be acting as a“catalyst”for the link of Li and Cu atoms because of the strong affinity of Li with Ag and Mg with Cu,and therefore the precipitation of T1phases is promoted.