Preparation of spherical zirconia powder in microemulsion system and its densification behavior

The water droplets in the microemulsion system of cyclohexane/water/TritonX-100/hexyl alcohol can act as the nano-reactors which solubilize zirconium oxychloride and ammonia separately. The precipitation reactions will take place in the confined spaces determined by the droplets size. The minute original reactors help us obtain nano-size spherical zirconia amorphous powder with uniform diameter distribution and weak aggregate. Such powder begins to crystallize at the temperature about 475 °C, and its shrinkage of densification will be elementarily finished from 1080 to 1280 °C. The powder is formed by dry pressing process. The 99% relative density and 100% tetragonal phase can be obtained when the green body is sintered at 1400 °C for 2 h.