Scanning electron microscopy characterisation of copper corrosion products (patina) formed in tropical humid climate

scanning election microscopy (SEM) has been used to investigate the patina formed on flat plate and wire open helix specimens of electrolytic Cu exposed to marine-coastal and rural-urban atmospheres in the tropical humid climate of the Yucatan peninsula in Mexico. More rapid corrosion rates observed in both types of atmosphere with the wire open helix specimens have been associated with differences in the morphology of the corrosion products, which are attributed to internal stresses generated during manufacture of the helix specimens or to their shape which allows more efficient capture of contaminants from the atmosphere.