In-situ monitoring of pitting corrosion of AZ31 magnesium alloy by combining electrochemical noise and acoustic emission techniques

• Published in: Journal of alloys and compounds Vol. 878; p. 160334
• Main Authors: Zhang, Zhen, Zhao, Zhanyong, Bai, Peikang, Li, Xiaofeng, Liu, Bin, Tan, Jibo, Wu, Xinqiang
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15.10.2021; Elsevier BV
• Subjects: Acoustic emission; Acoustic noise; Corrosion; Corrosion mechanisms; Electrochemical noise; Emission analysis; Magnesium alloy; Magnesium base alloys; Noise monitoring; Parameter identification; Pitting corrosion; Pollution monitoring; Signal classification; Electrochemical noise; Acoustic emission; Pitting corrosion; Magnesium alloy
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.160334

●Pitting corrosion of AZ31 Mg alloy was in-situ monitored under nature corrosion state by combining EN and AE techniques.●Three corrosion stages were identified according to EN and AE analysis results.●Detailed relationship between EN and AE parameters and different corrosion mechanisms is discussed. Pitting corrosion of AZ31 magnesium (Mg) alloy was in-situ monitored by combining electrochemical noise (EN) and acoustic emission (AE) techniques. The EN signals were analyzed by transient shape observation, Hilbert spectrum and recurrence quantification analysis (RQA) based on recurrence plot (RP). AE characteristic parameters including rise time, amplitude, absolute energy and peak count were adopted to classify the AE signals. According to the mutual information obtained by EN and AE measurements, three corrosion stages including film-forming process, pit initiation and pit propagation can be identified. The detailed relationship between the AE and EN parameters and different corrosion mechanisms is discussed. The main contribution of present study is to provide a feasible method to effectively monitor the self-corrosion process of Mg alloy.