Corrosion Products Formed on Copper exposed to humid SO₂‐containing atmospheres

Abstract

X‐ray diffraction analyses have been performed on samples of electrolytic copper (min. 99,9% Cu) exposed to humid atmoshperes at SO2‐supplies of 10 and 100μg SO2 per cm2 surface area per hour (10 and 100 ppm SO2. respectively). During the SO2 ‐exposures copper (II) sulphate (CuSO4 · 5 H2O) were the only crystalline phases formed in detectable amounts. Interruption of the SO2‐ supply resulted in the formation of copper (I) oxide and antlerite (CuSO4) · 2Cu (OH)2. During prolonged exposure brochanite (CuSO4 · 3Cu(OH)2) and langite (CuSO4· 3Cu(OH)2) and langite (CuSO4 · Cu(OH)2 · 2H2O) were also formed i. E. the Cu:S ratio of the basic copper sulphates increased with time. The formation of antlerite was preceeded by formation of an unidentified intermediate compound, probably a basic copper sulphate with a Cu:S ratio of less than three, and a simultaneous transformation of the copper (II) sulphate and copper (I, II) sulphite formed during the SO2‐exposure.

Characterization of Corrosion Products Formed on Copper in Urban, Rural/Coastal, and Hot Spring Areas

“…Laboratory chamber tests using corrosive gases such as sulfur dioxide under humid conditions have been performed to understand the corrosion behavior of copper. [4][5][6] Chamber test results showed that nitrogen dioxide and ozone present in the atmosphere accelerated copper corrosion through the effect of sulfur dioxide. Even with an extremely low sulfur dioxide concentration of, for example, 5 ppb, a black patina forms on a copper surface when the relative humidity exceeds 85%.…”

Characterisation of corrosion products formed on copper exposed at indoor and outdoor sites with high H2S concentrations

“…Although many laboratory studies have been made of atmospheric copper corrosion in an environment with a high concentration of corrosive gases, [16][17][18][19][20][21][22] few have focused on corrosion behaviour in an actual environment with a high H 2 S concentration. 23 In the study reported here, we investigated atmospheric corrosion of copper exposed indoors and outdoors in a hot springs area.…”

Etching Rate Enhancement of Copper by Adding Sulfur Compounds in Chemical-Mechanical Polishing Slurries

“…Although the corrosion phenomena of a Cu film in an environment containing sulfur or chlorine are well known, [6][7][8][9][10][11] in the CMP process, we have discovered that the Cu etching rate can be enhanced without affecting the pH by adding a small amounts of sulfur compounds to the slurry.…”