Goss texture intensity effect on fatigue crack propagation resistance in an Al-Cu-Mg alloy

Goss texture intensity effect on fatigue crack propagation (FCP) resistance in an Al-Cu-Mg alloy sheet is investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron back scattering diffraction (EBSD). Results show that sheet with high intensity Goss texture presents a lower FCP rate than relatively low intensity Goss-texture one. Greater crack deflections in the high intensity Goss texture sheet are observed during FCP, resulting in a rougher fracture surface and a greater roughness induced crack closure (RICC) effect, comparing to the low intensity Goss texture sheet. A modified crystallographic model is developed to calculate the twist angle and tilt angle between neighboring grains. Therefore, fatigue crack deflection occurred during FCP could be analyzed and understood.