微量In对Al-Cu-1.0Li-(Mg)合金微观组织与拉伸性能的影响

Influence of small Indium (In) addition on microstructures and tensile properties of Al-Cu-1.0Li-(Mg) alloy

摘要:

研究了Al-Cu-Li-(0.35Mg)-(0.2In)合金的拉伸性能、时效析出相类型及其分布。T6峰时效时，Al-Cu-Li合金的时效析出相为T1(Al2CuLi)和?? (Al2Cu)相。添加0.2%In时，T6态时效早期形成许多方块状的立方相Al5Cu6Li2，且随时间延长其尺寸保持稳定；同时，可促进? ?相析出；相应合金的时效响应加速，强度提高。同时添加In和Mg可抑制Al5Cu6Li2相析出，但促进T1相析出。In和Mg的复合微合金化效果小于2050铝锂合金中Ag和Mg的复合微合金化效果，因而In+Mg复合微合金化铝锂合金T6态强度低于Ag+Mg复合微合金化的2050铝锂合金。T8态时效时，时效前预变形产生的位错抑制了In元素单独添加和In+Mg复合添加的微合金化效果。

Abstract:

The tensile properties, aging precipitate type and distribution in Al-Cu-Li-(0.35Mg)-(0.2In) alloy were investigated. In the T6 aged Al-Cu-Li alloy, the aging precipitate are T1(Al2CuLi) and ?? (Al2Cu). As 0.2%In is added, many square-shaped cubic precipitates Al5Cu6Li2 are formed at early aging stage and their size keeps stable with aging time extension. Meanwhile, ? ? precipitation is advanced. The alloy?s aging response is therefore accelerated and its strength is enhanced. The combined addition of In+Mg suppresses the precipitation of cubic Al5Cu6Li2, but plays a role in promoting T1 precipitation instead. This role is smaller than that of combined addition of Ag+Mg in Al-Cu-Li alloy 2050, which results in a lower strength of the In+Mg micro-alloyed Al-Cu-Li alloy than that of the Ag+Mg micro-alloyed Al-Cu-Li alloy 2050. At T8 temper, the role of both In independent addition and In+Mg combined addition is suppressed by the dislocations introduced by plastic deformation prior to artificial aging.