Long-term thermal ageing of the 2219-T851 and the 2050-T84 Al-Cu alloys

Abstract

In this study, the influence of high temperature exposure on mechanical properties as well as on the microstructures of two Al-Cu alloys, has been investigated. Driven by an industrial will to use structural aluminium at higher temperature than usually stated, this work is focused on the characterization of the evolution of two commercial alloys, the 2219-T851 and the 2050-T84, induced by an ageing treatment of 1000 hours at 200°C. Careful TEM observations confirm the importance of the nanoscale precipitation and that the precipitate size and distribution strongly influence the mechanical properties of the studied alloys. Results unexpectedly show that the precipitates are more stable in time than the precipitates at this temperature. Regarding the mechanical properties related to ageing, it follows that the 2219-T851 alloy presents a reduced drop with time of its tensile test curves compared to the 2050-T84, thus a limited, and at least less pronounced, temperature dependence. For an industrial application on structural part, 2219-T851 alloy then appears to be a good candidate for long-term structural applications at intermediate temperatures.

Hardness Distribution of Al2050 Parts Fabricated Using Additive Friction Stir Deposition

“…Also, the T-phase (Al 20 Cu 2 Mn 3 ), AlCuLi, BCC, Al 12 Mn, and Al 3 Zr phases are the secondary phases at room temperature. T-phase is a precipitate phase [ 34 ].…”

“…The third-generation A–Li–X alloys [ 32 , 33 ] of 2050 are heat treated to produce stable tempers. The feedstock used for this study is T84 heat-treated [ 34 ]. For T84 heat treatment, first, the Al2050 undergoes solution heat treatment at 525 ± 5 °C followed by a water quenching.…”

“…For T84 heat treatment, first, the Al2050 undergoes solution heat treatment at 525 ± 5 °C followed by a water quenching. Then, the alloy goes through a ~4% compressive cold work, and finally, artificial aging at 155 ± 5 °C for 18 h is carried out [ 34 ]. The Al2050-T84 has a fine coherent microstructure [ 35 ].…”

Investigation on the Effect of a Chromium-Free Sealing Treatment for the Corrosion Resistance of AA2198-T851 after Tartaric Sulphuric Anodizing (TSA)

“…The mechanical properties of Al-Li alloys have been largely investigated. The microstructure and crystallographic texture of these alloys can be controlled in order to improve not only their mechanical behavior [5,14,15] but also their damage tolerance [5,6,14,[16][17][18][19].…”

Anodic Electrochemical Behaviors of 2219 Aluminum Alloy in NaNO3 and NaCl Electrolytes

“…Due to its high specific strength, favorable mechanical properties across a broad temperature range, high fracture toughness, and excellent stress corrosion resistance, 1,2 2219 aluminum alloy is frequently utilized in large, thin-walled structures like storage box bottoms, aircraft skins, and other aerospace components. 3 Despite the maturity of aluminum alloy cutting processes, machining large thin-walled structures often results in chatter and deformation.…”