Corrosion inhibition property and promotion of green basil leaves extract materials on Ti-Zr conversion composite coatings

作者：Tian, Yuqin; Zhong, Li; Sheng, Xinxin^*; Zhang, Xinya^*

来源：Advanced Composites and Hybrid Materials, 2022, 5(3): 1922-1938.

DOI：10.1007/s42114-022-00523-1

• Aluminum alloy
• Ti-Zr conversion coating
• Basil leaves extract
• Corrosion resistance
• Electrochemical

In this study, the extract obtained from green plant basil leaves was introduced into a corrosion medium NaCl solution to investigate the corrosion inhibition ability of basil leaves extract (BLE) on aluminum alloy (AA6061). The influence of BLE on the corrosion resistance of Ti-Zr conversion coatings (TiZrCCs) on AA6061 was also investigated. The protective performance of BLE on AA6061 was investigated through scanning electron microscopy (SEM). The TiZrCCs were characterized by SEM, X-ray photoelectron spectroscopy, and electrochemical tests including potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results of SEM show that BLE effectively prevented AA6061 from producing corrosion products during immersion in corrosive media. As for the TiZrCCs, SEM results reveal that BLE helped to form a more complete conversion coating and greatly improved the problem of coating cracks. Compared with the blank conversion coating, the corrosion rate of the coating with the introduction of BLE decreased from 0.043 to 0.007 mpy. In addition, density functional theory calculation was performed on several main substances in BLE, including methyleugenol, carvacrol, linalool, rosmarinic acid, and eugenol, and the reactivity and reaction sites of each molecule were theoretically analyzed. The results indicate that rosmarinic acid has the maximum electronegativity and the minimum hardness, as well as the best reactivity.

• 单位
  广东工业大学