Preparation of Al2O3-ZrO2 nano-powders and characteristics of the powders

Using scrap aluminium and ZrOCl2 · 8H2O as raw materials, pure ZrO2, Al2O3-50ZrO2 and Al2O3-20ZrO2 nano-powders with about 10nm in average diameter have been prepared by coprecipitation-gel method. ZrO2 in the powders is basically t phase. After calcinating in range of 600-1200°C, pure ZrO2 particles quickly grow up and transform from t into m phase. However, Al2O3-50ZrO2 composite powders are not liable to grow up, in which ZrO2 still exists as t phase. This result shows that ZrO2 nano-particle can stably exist at t phase at room temperature because of the size effect.