Fractograpic Observations and Effect of Stress Ratio on Fatigue Striations Spacing in Aluminium Alloy 2024 T351

In this paper, effect of stress ratio was investigated on macro and micro of fatigue crack growth rates (FCGRs) of Al-alloy 2024 T351. Microscopic fatigue crack growth rate present a change of slope with respect to the macroscopic fatigue crack growth rate. In addition, an increasing in stress ratio increases the fatigue life. Fractographic examination showed the presence of striations in Paris domain and secondary cracks at grain boundaries.