La protection du cuivre par siliciuration superficielle

A coating of Cu₅Si on Cu was prepared by treating copper with monosilane at 700°C and its behaviour in oxygen at high temperature investigated. The protective efficiency of this coating is good as no oxidation could be detected up to 600°C. At higher temperatures, the oxidation scale consists of three layers respectively of Cu₂O in contact with the metal, SiO₂, and CuO. The kinetic curves are of sigmoidal type. Their first part corresponds probably to a nucleation process leading to the formation of the silica layer. In the following stages, the reaction rate is assumed to be controlled by the simultaneous diffusion of oxygen and copper through the SiO₂ and CuO layers.