Effect of heating atmosphere composition and content on phase and morphology distribution of copper oxide layer

Abstract

Abstract When copper billet is heated in the rolling reheating furnace, some oxides which affect the surface quality may remain on the substrate. This study investigates the effects of different heating atmosphere compositions and contents (N2, O2, CO2 and H2O) on the micro-morphology and phase evolution of the exfoliated and residual oxides on copper billet surface by high-temperature oxidation experiments. The results show that the main phase of the exfoliated oxides is CuO attached to loose Cu2O, and the residual nodular oxides are also CuO which directly adhere to copper matrix; water vapour can increase the number and size of Cu2O particles on the interface between exfoliated oxide and copper matrix, and effectively reduces the number of residual nodular oxides; the vapour and its decomposition products may effectively eliminate the pores within the oxide layer and at the oxide-matrix interface, while CO2 may increase the pore size inside the oxide layer.