High-temperature phase equilibria of Cu–O–Al2O3system in air

Phase equilibria of Cu–O–Al2O3 system were experimentally investigated in a temperature range of 1100–1400°C under 0.21 atm oxygen pressure. The experiments were conducted employing a high-temperature equilibration and quenching method. Microstructures of the quenched samples were observed with scanning electron microscope. The phase compositions in the samples were analysed with electron probe microanalysis technique. Measured solubility of Al2O3 into the molten oxide ranged from 0.0 to 1.8 wt-%. A small solubility of Cu2O into Al2O3 was also observed ranging from 1.20 to 1.58 wt-%.