Surface and interface investigation of electrochemically induced corrosion on a quaternary bronze

Abstract

A quaternary (Cu‐Zn‐Sn‐Pb) cast bronze was submitted to an electrochemical corrosion experiment using an anodic polarization sweep. The surface/interface chemical analysis of the patina removed after the anodic polarization and the metallographic observations on the corroded bulk alloy highlight the onset of a dezincification process followed by a decuprification process, as well as the formation of a Sn‐enriched layer located at the interface patina‐bulk alloy. Different local corrosion patterns, as CuCl precipitation in pits, epitaxial growth of corrosion products on dendritic structures and of Cl‐enriched oxyhydroxides, are observed too. The results are discussed in comparison with experimental findings obtained in previous ageing tests performed on the same alloy in different chloride‐containing solutions. Copyright © 2014 John Wiley & Sons, Ltd.

Corrosion Behaviors of Outdoor Bronze Sculptures in an Urban–Industrial Environment: Corrosion Experiment on Artificial Sulfide Patina

“…The changes in the composition of the bronze base layer revealed that the Cu and Zn contents decreased, whereas the Sn and Pb contents relatively increased. These results are in line with the corrosion mechanisms of Cu-Zn-Sn-Pb and Cu-Zn-Sn alloys and the findings of previous studies [20,30,31,[37][38][39].…”

“…Several studies conducted under outdoor environmental conditions revealed that cuprite and cassiterite are mixed in the reddish-brown patina formed on top of the base metal. At S50 (2400 h), the artificial patina comprised cuprite (Cu: 79.33-84.38 wt%, Sn: 0.33-0.92 wt%), cassiterite (Cu: 55.71 wt%, Sn: 6.07 wt%), and a mixed layer of cassiterite and cu- The decrease in Cu and Zn is respectively attributable to the selective dissolution of Cu and Zn ions owing to the decuprification and dezincification processes within bronze; the cation moves toward the boundary through the patina inside the alloy, and the anion moves toward the inside of the alloy [37,39,40]. In particular, the initial corrosion is mainly (>90%) caused by Cu and Zn [31,38]; Sn forms a patina layer upon condensing as it is an insoluble corrosion product and is known to stabilize the patina through passivation [30,41].…”

Durable superhydrophilic/phobic surfaces based on green patina with corrosion resistance

“…[37][38][39] However, these methods have problems in attaining uniform brochantite structures on the copper surface and the artificially induced patinas tend to show poor adhesion so that post-process treatments are sometimes required for improving adhesion of the patina to the metal surface. 40,41 As a result, the application of patina has been limited despite its advantages. Therefore, it is necessary to develop a new strategy for achieving uniform and robust brochantite rapidly as a sustainable corrosion-resistant material even in seawater.…”

Analysis of the kinetic growth of an electrochemically formed bronze patina using the layer‐pore resistance model

“…At 0.5 mVs −1 the greatest protective layer is formed. Peak A 1 is related to the deposition of Cu + and Cu 2+ species, [ 35 ] leading mainly to the formation of Cu 2 O, while peak A 2 is associated with the formation of CuO or Cu(OH) 2 . However, the development of the anodic peak A' 1 at 5 and 7 mVs −1 is associated with the existence of an absorbed layer of (CuCl) ads .…”