Study On Surface Modification Of Nano-zirconia Ceramic Powders

The nano-zirconia powders have been prepared from inexpensive raw materials using convenient technique. Furthermore, the powders have been coated with carbon by CVD method and the biscuit have been sintered both in pressureless sintering and in vacuum. The sintering parameters and the sintered ceramic performance were studied, and the mechanism of coating was also analyzed.The nano-zirconia powders were prepared by precipitation-gel method, and the powders have good dispersivity and uniform grain size about 12nm. The powders were successfully coated with carbon by CVD method. It was found that after coated with carbon, the powders have good dispersivity and uniform carbon layer. The effect of surface modification parameter on coating results has also been discussed. It is shown that the coating layer is better when the reaction temperature is 750℃ and flow ratio of argon and acetylene gas is 10: 1.It has been proved that the coating layer effectively preventsthe grain growing during the sintering process, and the modification well affected the character of sintered ceramics. The relative density is 97.8% and grain size is about 92nm.