Dislocation ordering and texture strengthening of naturally aged Al-Cu-Mg alloy

• The good stability of the grain structure was analysed. • The characteristics of dislocations with specific orientation were systematically investigated. • The effect of texture strengthening on yield strength was explained from the perspectives of grain orientation, slip system type and misorientation. • The contribution of various strengthening mechanisms to yield strength is quantificationally, qualitatively evaluated. Stability of grain structure, dislocation ordering and strengthening mechanisms of the naturally aged Al-Cu-Mg alloy after solution treatment are investigated by using optical microscope (OM), scanning electron microscope (SEM), electron back-scattered diffraction (EBSD), X-ray diffraction (XRD) and transmission electron microscope (TEM). Results show that {100}<001>, {100}<110>, {110}<110> and {110}<001> slip systems can be activated after solution treatment, which can promote the formation of {110}<001> Goss texture. The combination effect of T-Al 20 Cu 2 Mn 3 phase and Goss-oriented grains with large Taylor factor makes the solution-treated alloys display excellent stability of grain structure. The enhanced yield strength of the alloy is ascribed to grain-refine strengthening, dispersed particles strengthening, dislocation strengthening and texture strengthening. The coarsening of the second phase is responsible for softening of the alloy after annealing at 400 °C + solution treatment at 475 °C.