Abstract

In the present study, a simple in situ hydrothermal method was used to fabricate Layered Double Hydroxide conversion coating at different treatment temperatures, times and pH values on the surface of AZ31 magnesium alloy. The films were characterized using XRD, FTIR, XPS, EDS and FESEM. The corrosion resistance of the coatings was evaluated by potentiodynamic polarization, electrochemical impedance spectroscopy and electrochemical noise techniques. The results confirmed the anion exchange ability of the LDH film. Moreover, the best results were obtained at 160 °C, 8 h and pH of 10. Dense and compact blade-like structures were obtained which exhibited appropriate corrosion resistance. The self-healing ability of the films was improved by increasing the LDH content of the film.

Graphic Abstract

摘要

在本研究中，采用简单的原位水热法在AZ31镁合金表面上以不同的处理温度，时间和pH值制备了双层氢氧化物转化膜。使用XRD，FTIR，XPS，EDS和FESEM对薄膜进行表征。通过电位动力学极化，电化学阻抗谱和电化学噪声技术评估了涂层的耐腐蚀性。结果证实了LDH膜的阴离子交换能力。此外，在160°C，8 h和pH为10时获得了最佳结果。获得了致密而紧凑的叶片状结构，显示出适当的耐腐蚀性。通过增加膜的LDH含量可以改善膜的自愈能力。

图形摘要