The Combined Effects of Gaseous pollutants and Sodium Chloride Particles on the Atmospheric Corrosion of Pure Copper
2005 (English)In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 61, no 11, 1022-1034 p.Article in journal (Refereed) Published
The atmospheric corrosion of pure copper has been investigated after the deposition of sodium chloride (NaCI) particles and exposure to humid air containing gaseous pollutants. Microgravimetry, Fourier transform infrared (FTIR) micro-spectroscopy, and scanning electron microscopy with x-ray microanalysis were used for the investigation of corrosion processes and products. The effect of NaCl particles on the mass gain was much higher than that of gaseous pollutants. With deposition of NaCl particles on the copper surfaces, the corrosion rate increased significantly, with severe corrosion attack mainly localized to the NaCl particle clusters. A similar corrosion rate was found, however, after exposure to pure humid air and to humid air containing gaseous pollutants, sulfur dioxide (SO2), ozone (O-3), nitrogen dioxide (NO2), and SO2 + NO2. The corrosion rate was not dependent on the concentration of the pollutants. However, this was not the case for the combination of SO2 and O-3, leading to a significantly higher corrosion rate at higher concentrations. Exposure of copper samples with NaCl particles deposited resulted in unevenly distributed corrosion product clusters, with a distribution of corrosion products that could be associated with the locations of the particle clusters. Around the particle clusters, the corrosion resulted in areas with different amounts of corrosion products. After 10 days of exposure to humid air containing 100 ppb SO2 and 100 ppb NO2 + SO2, cuprite (Cu2O), paratacamite (Cu-2[OH](3)Cl), carbonate (CO32-), and sulfate (SO42-) were observed mainly in the area of the original particle cluster, with some sutfate and copper hydroxysulfate also in the areas outside. After 10 days of exposure to humid air containing 100 ppb O-3 + SO2, cuprite (Cu2O), hydroxychloride (maybe paratacamite, Cu-2[OH](3)Cl), carbonate (CO32-), and sutfate (SO42-) were observed in the area of the original particle cluster. A circular zone containing brochantite (Cu-4[OH](6)SO4) was formed around and outside of the original particle cluster, and the formation of this phase was promoted by the presence of NaCl particles on the surface. The location of anodic and cathodic reactions during the corrosion process leads to the distribution of different corrosion products on the surface.
Place, publisher, year, edition, pages
2005. Vol. 61, no 11, 1022-1034 p.
atmospheric corrosion, copper, gaseous pollutants, nitrogen dioxide, ozone, sodium chloride, sulfur dioxide
IdentifiersURN: urn:nbn:se:kth:diva-6893DOI: 10.5006/1.3280618ISI: 000233180400002ScopusID: 2-s2.0-30644460774OAI: oai:DiVA.org:kth-6893DiVA: diva2:11734
QC 20100903. Uppdaterad från Accepted till Published (20100903)2005-09-272005-09-272014-12-01Bibliographically approved