Since the Australian scientist Gavie and others first discovered the phase change toughening mechanism of yttrium-doped zirconia in 1975, currently, advanced zirconia powder manufacturers at home and abroad, such as Tosoh of Japan and domestic Sanhuan Group, etc., all use yttrium doping to obtain stable tetragonal zirconia in patents cn102803180a, ep0140638b1, cn201510309285, etc.
At the same time, to prepare zirconium dioxide with good performance, the powder requirements also include the average particle size of the powder being less than 100nm, spherical shape, no hard agglomeration, high purity, uniform chemical composition, and narrow particle size distribution. Therefore, high-purity and highly dispersed ceramic powder is a key factor in determining powder performance. If the powder agglomeration is serious, it will affect the sintering of the ceramic and increase the sintering temperature. At present, the methods for preparing zirconia powder include hydrolysis, precipitation, microemulsion, hydrothermal, high-temperature spray pyrolysis, spray induction coupled plasma and freeze-drying. Among them, the precipitation method has simple process requirements And it is easy to add other oxides as stabilizers, but this method is easy to introduce other impurity elements, resulting in a decrease in purity. The colloidal precipitate formed is difficult to wash, has a slow filtration speed, and requires high-temperature calcination, and lumps are prone to agglomeration during the drying process. ; The hydrothermal method can directly obtain crystalline oxides from the solution, avoiding the traditional calcination process of converting hydroxides into oxides, and its particle size and morphology are controllable, reducing the introduction of external impurities and the production of hard polymers. It is possible, but the entire process cost is higher and the output is lower.
Therefore, it is necessary to provide an effective preparation method to obtain high-purity, high-dispersion and high-yield nano-zirconia powder.