Long-Term Corrosion of Copper in Hot and Dry Atmosphere in Turpan, China

Atmospheric exposure tests were conducted on pure copper exposed to the atmosphere for a four-year period in Turpan, China, a typical hot and dry environment. The experiments included weight-loss tests, morphology observations, composition analyses, and electrochemical techniques. The results indicated that the annual corrosion rate of pure copper was approximately 2.24 g/m(2)/year, and an uneven distribution of corrosion products was observed by scanning electron microscopy. This was attributed to the dehydration process that occurred during wet-dry and cold-hot cycles. The corrosion products mainly comprised cuprite (Cu2O) and atacamite (Cu2Cl(OH)(3)). Electrochemical measurements showed that deposits on copper improved its resistance to corrosion, but the protectiveness decreased with increasing temperature.