| An experimental study of the effect of scratches on the fatigue life and fatigue crack growth of Al 2024-T3 clad material has been conducted. The results show that Al 2024-T3 clad material is a scratch sensitive material with a drop in life as much as 95% for material with scratch depth of 100 {dollar}mu{dollar}m. Also, it has been found that cracks propagate faster in scratched samples than unscratched and at a lower stress intensity factor. In addition, a model that predicts the fatigue crack propagation of scratched samples has been developed. Furthermore, scanning electron microscope fractographes show that scratches generated microcracks which are responsible in decreasing the fatigue life of the material. |
