Influence of pre-rolling deformation on distribution characteristics of T₁ precipitate in artificially aged Al-Cu-Li alloy

The predeformation prior to artificial aging plays an important role in enhancing the properties of Al-Cu-Li based alloys. This study focused on investigating the impact of a large amount of prerolling (20%) on the orientation variation and distribution characteristics of T₁ precipitates in a rolled Al-Cu-Li alloy. The results revealed that T₁ phases precipitated in the same orientation were not strictly parallel within a grain, a small angle existed between different phases in the same direction due to the orientation fluctuation of the matrix induced by prerolling. The misorientation degree of the T₁ precipitates presented a slight expend tendency with increasing the aging time. Furthermore, the connection between this orientation distortion of the T₁ phases and the tensile properties was discussed. Additionally, it was found that the T₁ variants along different orientations were heterogeneously distributed, possibly due to the activation of different slip systems during the prerolling process and the variation in the number of nucleation sites among the nonparallel habit planes.