Analysis of empirical relation between microstructure, texture evolution and fatigue properties of an Al-Cu-Li alloy during different pre-deformation processes.

The microstructure and fatigue properties of Al-Cu-Li alloy sheets were investigated respectively under the conditions of without pre-deformation, 3% pre-stretching deformation and 8% pre-rolling deformation utilizing scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) in present work. Results show that the intensive Goss texture and relatively weaker Brass, Cube texture were formed in without pre-deformed alloy after aging treatment. The pole density level of Goss texture was decreased remarkably and the intensity of Brass, Cube texture was increased lightly after 3% pre-stretching deformation and 8% pre-rolling deformation. The magnitude order of fatigue crack propagation (FCP) rate of the alloy under different pre-deformation conditions was da dN pre − rolling  >  da dN pre − stretching  >  da dN non − predeformation in stage II (Paris regime). The combined contribution of T 1 phase with different size, amount and the intensity of Goss texture is the main factors affecting the FCP rate of Al-Cu-Li alloy. [ABSTRACT FROM AUTHOR]