Early stages of tin bronze corrosion in neutral aqueous chloride media: Electrochemical and FTIR investigations

Abstract

The corrosion behavior of tin bronze alloy equivalent to a Punic one was investigated in aqueous 0.5 M chloride electrolyte using potentiodynamic measurements. The electrochemical results showed selective dissolution of the major alloy component reflecting a decuprification process. FTIR characterization of the patina anodic layers showed the presence of various dehydrated and hydrated tin compounds with a few copper species suggesting the patina type I formation on the Cu10Sn bronze alloy. A kinetic model for the Cu10Sn bronze alloy dissolution in the chloride solution was developed. The reaction order with respect to chloride content was determined for the Cl− halide concentration domains. The low order value (about 0.22) was attributed to the Cl− adsorption intermediate step. The high reaction order value (about 2) reflected two determining steps of cuprous chloride complex formation. Two behaviors for the material were evidenced when varying the temperature. The values of the activation energy Ea, activation enthalpy ΔH* and activation entropy ΔS* were calculated and discussed.

Tribocorrosion behavior of nickel aluminum bronze in seawater: Identification of corrosion‐wear components and effect of pH

“…With regard to NAB alloys, a film of hydrated aluminum oxide/hydroxide is formed in seawater at any pH, which can quickly heal after rupture or damage. When exposed to the aggressive chloride-containing environments, this layer is generated by the complexation of Al and Cl − ions, then by hydrolysis to form the aluminum hydroxide layer, according to reactions (12) and (13): Thus, in corrosive seawater, the corrosion resistance of NAB alloys is derived from the formation of a protective oxide film, containing both copper and aluminum oxides. This film is copper-rich in the outer layer and rich in aluminum adjacent to the base metal, as demonstrated by Schüssler and Exner.…”

“…[4][5][6] The corrosion behaviors of NAB alloys are mainly dependent on metallurgical composition, which is of significant importance on determining the microstructure, and environmental variables, including pH, [7] temperature, [8] chlorinity, [9] etc. Among these factors, the influences of pH on the corrosion mechanism of NAB alloys are critical and attract the attention of many researchers, [10][11][12][13] given that the relative nobility of NAB phases alters in chloride media at different pH values, i.e., occurrence of selective phase corrosion.…”

Surface Characterization of the Corrosion Product Layer Formed on Synthetic Bronze in Aqueous Chloride Solution and the Effect of the Adding of Juniperus Communis Extract by X-Ray Photoelectron Spectroscopy Analysis

“…Bronze alteration phenomena in different mediums have been studied in many researches [1][2][3][4][5][6].The electrochemical behavior of archeological bronze (Cu-10Sn)in neutral aerated NaCl solution has been recently investigated through potentiodynamic measurements using a rotating disk electrode. The anodic J-E curve exhibits three main regions, that appear closely related to the formation of different corrosion species [7].…”

Effect of sulphate on the corrosion behavior of bronze under a chloride‐containing thin electrolyte layer

“…Generally, when bronze is exposed to a clean, humid atmosphere, a passive layer of copper oxides is formed on its surface. However, when it is exposed to aggressive atmospheric environments, such as water contaminated by chloride, carbonate, nitrate, or sulphate, it usually suffers from significant corrosion . It is accepted that the atmospheric corrosion of bronze occurs under thin electrolyte layers (TELs) and is a process predominantly controlled by electrochemical reactions .…”