Role of Pre-Deformation on Aging Precipitation Behavior of Al-Cu-Li Alloys

摘要

Predeformation on tensile properties and microstructure of three Al-Cu-Li alloys, 1460, 2050 and 2A96 was investigated. The strength of the alloys is enhanced by the predeformation. Meanwhile, predeformation impacts the precipitation of T1 (Al_2CuLi) and θ'(θ'') (Al_2Cu) phases. The precipitation (nucleation rate) of Tl is accelerated by the predeormation, and the effect is increased with the predeformation degree. While, effect on θ'(θ'') precipitation is dependent on the alloy composition feature. In the 2A96 alloy with a medium Cu/Li ratio, it is decelerated by the predeformation. In the 2050 alloy with high Cu/Li ratio and 1460 alloy with low Cu/Li ratio but subjected to two-step aging at 130°C and 160°C, the θ'(θ'') precipitation is accelerated at lower predeformation but decelerated at higher predeformation.