Corrosion behaviour of bronze in urban environments: influence of tin content

Abstract

In this paper, the influence of the tin content on the corrosion behaviour of copper alloys was investigated. Three different bicomponent bronze alloys were exposed to a natural urban environment. The kinetic corrosion processes and the patina properties were monitored using the open circuit potential, electrochemical impedance spectroscopy and spectrocolorimetry. Results show that the bronze corrosion behaviour improves upon increasing the tin content. In addition, the mechanism of the patina formation is different for the three alloys.

Keywords:

• Copper alloys
• Corrosion
• Electrochemical techniques
• Spectrocolorimetry

The authors gratefully acknowledge Professor S. Natali (Sapienza) for being able to use the spectrocolorimeter. L. Gianni is also indebted to the ENVI^ART COST programme that funded the beginning of the research with a short term scientific mission.