Influence of Pre-deformation on Aging Precipitation Behavior of Three Al–Cu–Li Alloys

Abstract

The influence of pre-deformation on aging precipitates of three near peak-aged Al-Cu-Li alloys, 1460 alloy with a low Cu/Li ratio (1.46), 2050 alloy with a high Cu/Li ratio (4.51) and 2A96 alloy with a medium Cu/Li ratio (2.97), was investigated. The strength of the aged alloys is enhanced by the pre-deformation. The effectiveness of pre-deformation on precipitates is dependent on the alloy's composition. With increasing the pre-deformation, the population density of T1 (Al 2 CuLi) precipitates increases in all three Al-Cu-Li alloys and their diameter decreases in 2050 and 2A96 alloys, and the greatest effectiveness is observed in 2A96 alloy. The pre-deformation also increases the population density of h 0 (Al 2 Cu) precipitates and decreases their diameter in 2050 and 2A96 Al-Li alloys, but the effectiveness is smaller compared to that on T1 precipitates. In 1460 alloy subjected to two-step aging at 130°C for 20 h followed by 160°C for 12 h, the main precipitates are d 0 (Al 3 Li). At 2%-6% pre-deformation, GP-I zones form and pre-deformation displays little influence. Eight percentage pre-deformation promotes h 00 /h 0 precipitation and increases their population density.

Effect of pre-deformation and artificial aging on fatigue life of 2198 Al-Li alloy

“…However, the strain energy as well as interfacial energy between δ′ and the matrix are low, they tend to be dissolve in the matrix by homogeneous nucleation, so the precipitated morphology and quantity of the δ′ are not affected by the pre-deformation [3,33]. Meanwhile, the growth of T 1 consumes Li atoms in the solid solution.…”

“…The aluminum-lithium alloys have attractive applications in the aerospace industry owing to their lower density, better strength and higher stiffness comparing to the conventionally commercial 2xxx and 7xxx series aluminum alloys [1][2][3][4][5][6][7][8]. However, insufficient plasticity, toughness and obvious anisotropy prevent their universal uptake [9].…”

Enhancing the Corrosion Resistance of Al–Cu–Li Alloys through Regulating Precipitation

“…The mechanical and corrosion properties of Al-Cu-Li alloys are related to intermetallic phases such as the T series (Al 2 CuLi, T 1 ; Al 5 CuLi 3 , T 2 ; Al 7 Cu 4 Li, TB), δ (Al 3 Li) and θ (Al 2 Cu) precipitates. The distribution and size of these precipitates are significantly influenced by thermo-mechanical processing [4,5]. The T 1 phase is the primary strengthening precipitate in Al-Cu-Li alloys (such as the 2195, 2050 and 2090 alloys).…”

Improved Properties in Relation to Fine Precipitate Microstructures Tailored by Combinatorial Processes in an Al–Cu–Mg–Si Alloy

“…For Al-Cu-Li alloys, the pre-deformation affects the macroscopic performance by affecting the competitive relationship of T1 and θ′ phase, the result of which is strongly related to the alloy composition [10]. For Al-Zn-Mg-Cu alloys, the tensile strength of the aged 7050 alloy with 2.3% pre-stretching is lower than that of samples without pre-stretching, resulting from the precipitation of rod-shaped η phase induced by the dislocation [11].…”