Megahed Mohamed M, AbdElRhiem Eman, Atta Wesam, Ghany Nabil Abdel, Abdelbar Mohamed
Conservation Department, Faculty of Archaeology, Fayoum University, Faiyum, Egypt.
Mining and Metallurgy Engineering Department, Tabbin Institute for Metallurgical Studies (TIMS), Tabbin, Helwan, 109, Cairo, 11421, Egypt.
Sci Rep. 2025 Feb 6;15(1):4473. doi: 10.1038/s41598-025-88370-0.
Brass (Cu-Zn alloy) used in the crescent of the Al-Maradani Mosque pulpit is subjected to corrosion under certain conditions, such as exposure to polluted air, oxidizing acids, and compounds containing sulphur or ammonia. This study aimed to evaluate the effectiveness of palm kernel oil extract (PKO) as a green corrosion inhibitor for protecting brass artifacts. The crescent was analyzed using metallographic microscopy, scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX), and X-ray diffraction (XRD) to identify its alloy composition, microstructure and corrosion products. The analyses confirmed the crescent was made of a brass alloy (Cu-Zn) and formed by hammering, with corrosion layers composed primarily of cuprite and clinoatacamite, covered by dust containing calcite and quartz. The corrosion protection efficiency of the PKO was evaluated using brass coupons, simulating the artifact of the alloy. Electrochemical methods, including the open circuit potential (OCP), Tafel, and electrochemical impedance spectroscopy (EIS), were used to assess the performance of palm kernel oil on brass coupons at different concentrations (1, 3, 5, 7%). Electrochemical tests showed that corrosion inhibition efficiency increased with higher palm kernel oil concentrations, with the 7% concentration exhibiting the highest corrosion protection, up to 99.7%.
位于阿尔-马拉达尼清真寺讲坛月牙形装饰处的黄铜（铜锌合金）在某些条件下会遭受腐蚀，比如暴露于污染空气中、氧化性酸以及含硫或氨的化合物中。本研究旨在评估棕榈仁油提取物（PKO）作为一种绿色缓蚀剂对黄铜制品的保护效果。利用金相显微镜、配备能量色散X射线（EDX）的扫描电子显微镜（SEM）以及X射线衍射（XRD）对月牙形装饰进行分析，以确定其合金成分、微观结构和腐蚀产物。分析证实，月牙形装饰由黄铜合金（铜锌合金）制成，通过锤打成型，腐蚀层主要由赤铜矿和斜氯铜矿组成，上面覆盖着含有方解石和石英的灰尘。使用黄铜试片模拟该合金制品，评估了PKO的缓蚀效率。采用包括开路电位（OCP）、塔菲尔曲线以及电化学阻抗谱（EIS）在内的电化学方法，评估了不同浓度（1%、3%、5%、7%）的棕榈仁油对黄铜试片的性能影响。电化学测试表明，缓蚀效率随着棕榈仁油浓度的升高而增加，7%浓度时的缓蚀效果最佳，缓蚀率高达99.7 %。
