Preparation of a ZrO2-Al2O3 nanocomposite by high-pressure sintering of spray-pyrolyzed powders

ZrO2 - Al2O3 powders were synthesized by spray pyrolysis. These powders wer e sintered at 1 GPa in the temperature range of 700-1100 degrees C. The mic rostructural evolution and densification are reported in this paper. The ap plication of 1 GPa pressure lowers the crystallization temperature from sim ilar to 850 to <700 degrees C, Similarly, the transformation temperature un der I GPa pressure for gamma --> alpha - Al2O3 reduces from similar to 1100 to 700-800 degrees C range, and that for t --> m ZrO2 reduces from similar to 1050 to 700-800 degrees C range. It was possible to obtain highly dense nanocrystalline ZrO2-Al2O3 composite at temperatures as low as 700 degrees C, The effect of high pressure on nucleation and transformation of phases is discussed.