| In this work, the normal pressure hydrothermal method and polyvinyl alcohol gel technology were adopted to prepare ZrO2 nanoparticles by using ZrOCl2·8H2O, PVA and glutaraldehyde as raw material, Y(NO3)3·6H2O as dopant and NH3·H2O as the Precipitant respectively. The green compacts were formed by prilling, dry Pressing and were sintered by ordinary sintering. The effect of calcining temperature on the density, bending strength, microstructure and property of sintered bodies were studied. The phase composition of the powders was detected by X-ray diffraction (XRD);the morphology, size and distribution of the particles were studied by transmission electron microscopy (TEM); the calcining temperature of the gel powders was determined by thermogravimetry differential thermal analysis (TG-DTA);the microstructure of sintered bodies was analyzed by scanning electron microscopy (SEM);and the mechanical Property of sintered bodies was characterized by bending strength, the main experiment tasks and results are as follows:1. The influence of reaction conditions on the crystal form of products was studied. The reaction time (Id,3d,5d and 7d), pH value (8,9,10,11,12,13 and 14) and concentration of precursor (0.1mol/L,0.3mol/L,0.4mol/L and 0.5mol/L) were adjusted to prepare, measure the phase composition and size of products. At last the ZrO2 nanoparticles, which contain the monoclinic and tetragonal phase and the average grain diameter is about 10nm, were obtained under the following conditions: T=95℃, pH=14, t=3d. And the results showed that the productivity of ZrO2 would be improved with the increase of concentration of precursor.2. The influence of the weight of ZrOCl2·8H2O,the concentration of PVA,the concentration and volume of the cross-linking agent on the stability of gel were researched. The results indicated that the gelatinization time will shorten with the increase of addition of ZrOCl2·8H2O and concentration of PVA. On the other hand, the concentration of the cross-linking agent has direct influence on the gelatinization. The best technological parameter and process were obtained:firstly adding 30-40g ZrOCl2·8H2O and 10ml glutaraldehyde(25%) to 50ml PVA(2%);then heated in water bath at 45℃for 10 minutes to form the stabilized gel;after aging for a period of time, put the gel to NH3-H2O for immersing; lastly the gel was dried and calcined so as to get the ZrO2 powders, which is about 20nm in size and has the narrow sized distribution, good dispersity. At the same time, the doped experiments with 3% also was done, the results showed that stabilized tetragonal phase zirconia can be obtained successfully by this technology.3. As analyzing the density, bending strength, shrinkage ratio and SEM of samples sintered at different temperature, the powders' sintering character of polyvinyl alcohol gel technology is superior to the normal pressure hydrothermal method. So low-temperature sintering can be achieved by adopting this technology. Because of the add of Y3+, doped sample has higher density and flexural strength value, which benefited form the restraining effect of dopant to the growth of grains.
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