The atmospheric corrosion of copper at two sites in Portugal: a comparative study

• Published in: Corrosion science 2004-03, Vol.46 (3), p.547-561
• Main Authors: Fonseca, I.T.E, Picciochi, R, Mendonça, M.H, Ramos, A.C
• Format: Article
• Language: English
• Subjects: A. Copper; Applied sciences; B. Weight loss; C. Atmospheric corrosion; Corrosion; Corrosion environments; Corrosion mechanisms; Exact sciences and technology; Kinetics; Metals. Metallurgy; SEM/EDS; X-rays diffraction
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/S0010-938X(03)00176-8

This paper presents a comparative study on the atmospheric corrosion of copper, at two sites, in Portugal, with exposures started in two different seasons (summer and winter). Particular attention is devoted to the initial stages of the corrosion process. The levels of pollutants, namely of SO 2 and chlorides, in both atmospheres, have been measured, over the periods from August 1999 to July 2000 and from November 2000 until July 2001. Climatic data for both sites and both periods has been collected and analysed. Kinetics of the corrosion process (weight losses) have shown to be described by: Δ m= kt 0.6 and Δ m= kt 0.4, with k equal to 3.4 (g m −2 month −0.6) and 17 (g m −2 month −0.4), for the one year exposures, started in summer, at the urban and maritime atmospheres, respectively. Exposures started in winter, at the urban atmosphere, have lead to kinetics described by Δ m= kt 0.7 with k=5.0 (g m −2 month −0.7). The chemical composition and the morphology of the copper patinas, corresponding to exposures of 2 and 12 months, at the two sites, are compared as well as the morphology of the corroded surfaces.