Oxidation Behavior of Cu–Si Alloys with Different Compositions

To study the effect of Si content on high-temperature oxidation of alloys, the oxidation behaviour of casting (denoted as CA) Cu–Si alloys was studied at 700 and 800 °C in pure O₂. The oxidation kinetics shows that the oxidation rate of each alloy increases with the increasing temperature, and that as the content of Si in alloys increases, the oxidation rates of both alloys are reduced. The oxide scales were examined by XRD, SEM and EDX. The results show that both of the alloys formed similar complex scales like CuO → Cu₂O → Cu₂O + SiO₂ → internal oxidation zone, and did not form continuous layers of SiO₂. The affection mechanism was also discussed.