Roles of alumina, a base catalyst, a fine particle effect on the metastable phase Stabilization of the tetragonal zirconia at temperatures of 600-800 degrees C

摘要

Nanoparticles of the tetragonal alumina-stabilized zirconia were synthesized from zirconium salt of ZrOCl2 center dot 8H(2)O and approximately 23 wt % alumina stabilizer with ammonia as a base catalyst and sucrose as a gelling agent at a room temperature. In the preparation process of nanoparticles of alumina-stabilized zirconia, the calcination was conducted at temperatures of 500-800 degrees C. The calcined powder was analyzed and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) studies. The tetragonal phase of ZrO2 started to crystallize at a low temperature of 500 degrees C. Further phase transformation of the alumina-stabilized zirconia maintained the tetragonal ZrO2 at 600 degrees C. Besides, the addition of sucrose by weight ratio of 1 : 6 to the total weight precursors produced nanoparticles of alumina-stabilized zirconia less than 20 nm in size at that temperature. The tetragonal phase of ZrO2 was stable and no transition alumina was identified at 800 degrees C. It is suggested that alumina is in solid solution in the tetragonal zirconia polymorph at that temperature. The typical SEM images show high agglomeration of ultrafine microstructures of alumina-stabilized zirconia nanoparticles at that temperature. The results indicate that the method represents an effective methodology for the preparation of alumina-stabilized zirconia nanoparticles at a lower temperature than 800 degrees C.