Effect of a prior stretch on the aging response of an Al-Cu-Li-Ag-Mg-Zr alloy

Formation mechanism of precipitate T1 in AlCuLi alloys

“…4c and d, even at the very end of the edge of precipitates, the differences are manifested in the following aspects: (1) The contrast of atomic columns in Al-Cu(1) layers of T 1 -precipitate presents alternately darker and brighter, while the contrast in Cu-rich layers of GP T1 zone is homogenous. (2) The contrast between Cu-rich layers in T 1 -precipitate is darker compared to that in GP T1 zone. It indicates indirectly that the very small T 1 -precipitate in very early stage of aging covered by thick Al matrix would not present homogenous contrast in Cu-rich layers as Fig.…”

“…Their ultra-high strength is attributed to a great number of precipitates forming during ageing, including lenticular or spherical δ′ (Al 3 Li) phase, platelet-shaped θ′ (Al 2 Cu) phase usually coated with δ′ phase and GP zones, as well as platelet-shaped T 1 (Al 2 CuLi) phase [2,3]. Among these precipitates, the T 1 precipitates were considered to be mainly responsible for the strength of aged commercial Al-Cu-Li alloys [4].…”

Experimental investigation of tension and compression creep-ageing behaviour of AA2050 with different initial tempers

“…Kumar et al [8] have investigated the ageing process of Al-Cu-Li alloys with initial tempers of T3 and T4 and concluded that both precipitates from natural ageing and dislocations from pre-stretch in the initial temper would influence the subsequent ageing process. In addition, it has been reported that dislocations induced by the pre-stretch facilitate the nucleation of T1 precipitates, thus accelerating ageing progress and promoting strength [10,11]. By contrast, little research has been published on the creep behaviour of Al-Cu-Li alloys.…”

Microstructural development of adiabatic shear bands formed by ballistic impact in a WELDALITE 049 alloy

“…Because the WELDALITE alloy has a lithium content about half that of the 2090 or 8090 Al-Li alloys and the ␦'-(Al 3 Li) phases are mostly dissolved during precipitation and growth of the T 1 phases, [22,23,24] they are not well observed in the WELDALITE alloy. Because the WELDALITE alloy has a lithium content about half that of the 2090 or 8090 Al-Li alloys and the ␦'-(Al 3 Li) phases are mostly dissolved during precipitation and growth of the T 1 phases, [22,23,24] they are not well observed in the WELDALITE alloy.…”