فهرست نشریات علمی دسترسی آزاد ایران

This study investigates the microstructure and stress corrosion cracking behavior of 7075 aluminum alloy upon exposure to a corrosive solution in accordance with ASTM G47 standard. Initially, specimens were prepared under specific conditions and subjected to the corrosive environment for a total duration of 60 days, following a 7-day cyclic schedule (exposure times: 48, 168, 336, 504, 672, 840, 1008, 1176, and 1344 hours). The microstructure of the samples was subsequently analyzed using Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Spectroscopy (EDS). The microstructural analysis revealed that the 7075 alloy is highly susceptible to localized corrosion. Owing to the presence of precipitates at the grain boundaries, intergranular corrosion was observed within the first 72 hours. Over time, this intergranular corrosion transitioned into pitting and exfoliation corrosion. Furthermore, the results demonstrated that specimens which were only subjected to flattening, without undergoing subsequent cold working or stress relief processes, did not exhibit any corrosion. In contrast, specimens that were cold-worked via bending, but not treated with shot peening, showed evidence of corrosion. Notably, in samples where shot peening was applied, this process was found to effectively delay the corrosion rate. Essentially, shot peening improves surface integrity and enhances physical properties, thereby increasing the alloy's resistance to stress corrosion cracking.