Preparation of ZrO<sub>2</sub> Micro Beads by Sol-Gel Method

Abstract

ZrO2 micro beads are widely used as abrasive media in many areas. This paper introduces a sol-gel process for preparation of ZrO2 micro beads. First, zirconium nitrate solution and urea were mixed to prepare the sol, then the sol was converted to uniform droplets by vibrating dispersion method. The droplets were emitted from the nozzles into an ammonia solution. Along the way from the nozzle to ammonia solution, the liquid droplets first form spherical shape by their surface tension in air, and were then surface-hardened through ammonia gas. The microspheres complete gelation in the ammonia solution. The gel spheres were treated successively by aging, washing, drying, calcination and sintering to yield ZrO2 ceramic micro beads. The crystal structure of micro beads was examined by X-ray diffraction (XRD). The microstructure of the micro beads was observed by scanning electron microscopy (SEM). The results indicate that the sol-gel process can be used to prepare ZrO2 ceramic micro beads with good sphericity and uniform distribution of diameter.