Microstructure and thermal analysis of Cu-Cu2O eutectic – Can we mimic archeological remains?

An attempt was performed to reproduce in laboratory the microstructure observed in ancient artefacts and metallurgical remains made of nearly pure copper cast under ambient atmosphere. Two samples of pure Cu were prepared for thermal analysis, then heated and held for various times in the liquid state under ambient air for oxidizing, and finally cooled down at given rate. It was observed that a thick Cu2O oxide layer developed around the samples which gives the metal the same outer appearance than reported for metallurgical remains, namely a highly oxidized surface with large voids. Further, the microstructure of the metal consisted of (Cu) or Cu2O dendrites and a (Cu)-Cu2O eutectic showing strong similarity with the observations made on remains and artefacts