Scanning electrochemical cell microscopy: A powerful method to study the intergranular corrosions of archaeological silver artifacts

Intergranular corrosion is considered the major cause of the embrittlement of archaeological silver artifacts. However, the galvanic attack between different phases is a rather complex process involving the differences in local electrochemical activities that have been proved difficult to further understand with existing techniques. Herein, a visualized quantitative procedure of studying intergranular corrosions is established in this work through the preparation of a simulated silver-copper alloy sample and application of the scanning electrochemical cell microscopy (SECCM) as a high spatial resolution method. The macroscopic corrosion behavior according to the droplet corrosion tests is highly consistent with the results of local electrochemical activities acquired from SECCM. Meanwhile, the possibility of studying intergranular corrosion behavior in different soil environments by SECCM is demonstrated through a corrosion test under standardized ion conditions, which indicates a bright future of this method in the field of corrosions. (C) 2020 Elsevier Masson SAS. All rights reserved.