Preparation and Microstructure of Al2O3/GdAlO3 Eutectic Ceramic by Plasma Melting

According to the eutectic percentage, the sample that was rapidly melted at high temperature by the plasma technology was prepared with 77mo1% Al2O3 and 23mol% Gd2O3. The samples were cooled in two different ways i.e. air cooling and water quenching. Phases and microstructures of the investigated sample were examined by X-ray diffraction and field-emission scanning electrical microscopy. The results show that Al2O3/GdAlO3 eutectic ceramics are both obtained by plasma rapid melting, though cooled in different ways. Their microstructures that both consist of two partially continuous phases are free of pores and impurities. Compared with the air cooled sample, finer eutectic microstructure whose spacing is approximately 0.2 mu m is gained by the water quenching method.