| The crystallization process of zirconia is studied systematically. When the pH is less than 7, zirconium can not precipitate completely so the pH choose 8 for the experiment.The zirconia samples are calcinated at different temperature by impregnation-crystallization and precipitation-crystallization crafts respectively for adding W,P. The influence of zirconia crystallization process with different additives is study by TG-DSC and XRD.The conclusion show the growth of grain and the phase transition from t-ZrO2 to m-ZrO2 are significantly inhibited because of adding boron.With the increasing of boron content, impregnation-crystallization process is more conducive to the formation of t-ZrO2 than precipitation-crystallization process which is good for t-ZrO2 at higher temperature. The higher roasting temperature,the more conducive to m-ZrO2. In the appropriate roasting temperature, surface of samples by impregnation-crystallization process is larger than precipitation-crystallization process.The crystallization of ZrO2 and phase transformation process between metastable t-ZrO2 are significant inhibited for adding W. Precipitation-crystallization process is more conducive to the formation of t-ZrO2 than impregnation-crystallization process, but with the increasing of tungsten content there are no obvious changes. m-ZrO2 is favorable formed at high calcination temperature. surface of ZrO2 will increas by adding appropriate the content of W.The inhibit to the crystallization of ZrO2 is more stronger while P was added..It can delay the crystallization of ZrO2 and the phase transition from t-ZrO2 to m-ZrO2. Roasting temperature is not enough high, the influence of the crystallization of ZrO2 and phase transformation is not obvious because of different crafts.'P is most effective by comparing the influence of adding B,P,W in ZrO2.Conclude that only small part get crystallizated.
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