Evaluation of the Corrosion Behaviour of Copper in Different Corrosive Media Using Weight Loss Measurements

Abstract

Copper is different from most other metals because it combines corrosion resistance with high electrical and thermal conductivity. It also has good formability and machinability and its strength can be improved by alloying, although copper alloys generally lose strength at high temperatures. Copper exhibits good resistance to urban, marine, and industrial atmospheres, as well as to water. It is considered a noble metal, and hydrogen evolution is usually not part of its corrosion process, which contributes to its good corrosion resistance in many environments. Copper is not attacked by non-oxidizing acids in the absence of oxygen or other oxidizing agents. However, when oxidizing agents such as nitric acid are present, corrosion can occur. For example, the reaction between copper and dilute sulphuric acid is not thermodynamically favourable under normal conditions. In the presence of dissolved oxygen, however, corrosion proceeds and copper sulphate and water are formed. In such cases, the main cathodic reaction is the reduction of oxygen to hydroxide ions. This corrosion behaviour is applicable to both copper and its alloys.