Akademik Veri Yönetim Sistemi
INTERNATIONAL JOURNAL OF FATIGUE, cilt.204, 2026 (SCI-Expanded, Scopus)
In aerospace applications, surface treatments are widely employed to enhance the corrosion resistance of aluminum alloys as part of sustainability-oriented strategies; however, such treatments and surface defects degrade fatigue performance and compromise long-term structural integrity. This study focuses on the long-life fatigue behavior of forged aerospace grade 7050-T7452 aluminum alloy under various surface conditions, including chromic acid anodizing, sulfuric hard anodizing, and artificially introduced surface defects (corroded pits and scratches). Fatigue performance was characterized through Bayesian-based S-N curve modeling, enabling probabilistic assessment of fatigue life. Fractography was employed to identify crack initiation sites and assess the role of microstructural and geometrical discontinuities. Sulfuric hard anodizing exhibited the most pronounced reduction in fatigue performance up to 66.23%, primarily attributed to increased oxide layer thickness and tendency to promote multiple crack initiation. In contrast, chromic acid anodizing exhibited negligible fatigue degradation in the endurance limit region. At 5x107 cycles, fatigue knockdown factors were quantified as 2.81%, 66.23%, 55.58%, and 61.77% for chromic acid anodizing, sulfuric hard anodizing, corroded pit, and scratch groups, respectively. Surface defects significantly reduced fatigue strength by promoting multiple crack nucleation and accelerating crack propagation. Defect-tolerant approach was assessed using a modified Kitagawa-Takahashi diagram based on root area parameter and El Haddad model.