微量In对Al-Cu-1.0Li-(Mg)合金微观组织与拉伸性能的影响（英文）

Influence of Small Indium Addition on Microstructures and Tensile Properties of Al-Cu-1.0Li-(Mg) Alloy

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(Al_2CuL i)和θ'(Al_2Cu)相。添加0.2%In时,T6态时效早期形成许多方块状的立方相Al_5Cu_6Li_2,且随时间延长其尺寸保持稳定;同时,可促进θ'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Al_5Cu_6Li_2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。

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 precipitates are T1(Al2CuLi)and θ′(Al2Cu).As 0.2%In is added,many squareshaped cubic precipitates Al5Cu6Li2 were formed at the early aging stage and their sizes keep stable with the extension of aging time.Meanwhile,the θ' precipitation is promoted,therefore the aging response of alloy is 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 the combined addition of Ag+Mg in 2050 Al-Cu-Li alloy,which results the strength of the In+Mg micro-alloyed Al-Cu-Li alloy being lower 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 are suppressed by the dislocations introduced by plastic deformation prior to artificial aging.