The presence and consequences of precipitatefree zones in an aluminium-copper-lithium alloy

Strengthening mechanisms, deformation behavior, and anisotropic mechanical properties of Al-Li alloys: A review

“…The micro-void and micro-crack nucleation should occur along the intersections of the slip bands and grain boundaries, and the consolidation of these nucleation locations can cause intergranular fracture, as shown in Fig. 7 b [66] , [75] , [82] . Similar planar slip deformations have been observed in other precipitation-hardened Al alloys, but the influence is exceptionally serious in Al-Li alloys due to the improvement in the strain localization on both the grain boundaries and grain boundary triple junctions caused by the Al 3 Li PFZs.…”

“…Similar planar slip deformations have been observed in other precipitation-hardened Al alloys, but the influence is exceptionally serious in Al-Li alloys due to the improvement in the strain localization on both the grain boundaries and grain boundary triple junctions caused by the Al 3 Li PFZs. The improved strain localization promotes a generous “localized” deformation that occurs before the macroscopic deformation [82] , [83] , [84] . When the localized deformation is linked to the “local” stress concentrations and the associated micro-void or micro-crack nucleation in the intermediate and coarse grain intermetallic phases, the result is poor ductility and fracture toughness [84] , [85] .…”

Microstructure and mechanical properties of newly developed aluminum–lithium alloy 2A97 welded by fiber laser

“…During welding, the dissolution of precipitates, solute segregation, as well as the evaporation of alloying elements (Mg content varying from 0.47% in BM to 0.36% in weld, for example) destroy the hardened structure. The mechanism of strengthening by coherent and partially coherent phases such as δ 0 , θ 0 , is dislocation shearing [1,37], which can be expressed by Eq. (1), while that by incoherent precipitates such as T 1 , S 0 , is dislocation bypassing, expressed by Eq.…”

“…The planar slips associated with δ 0 shearing lead to localized pileups of dislocations at grain boundaries and grain boundary triple junctions, and when they are combined with eutectics formed due to segregation, much high strain and stress concentrations occur, then the microcracks nucleate subsequently, and grow readily along the grain boundaries [37,38].…”

Auger electron spectroscopy analysis of grain boundary microchemistry in an Al–Cu–Li alloy

“…Based on the above introduction, two key factors remain in need of further work to better understand the IGC/IGSCC in Al-Cu-Li alloys. These include (i) the detection and rationalisation of the role of Li in the sensititsation/resensitisation behaviour, and (ii) the microchemistry and microstructure at grain boundaries [21][22][23][24][25][26].…”