【作者】 梁玥；

【导师】 齐龙浩；

【作者基本信息】 清华大学 ， 材料科学与工程， 2014， 硕士

【摘要】 氧化锆陶瓷材料具有高强度、高硬度以及耐热、耐腐蚀等的优良性能，它在常温下能够绝缘，在高温下能够导电，不论是作为功能陶瓷还是结构陶瓷都得到了十分广泛的应用。相应的，高性能低价格的氧化锆粉体具有很大的市场需求量。然而，目前氧化锆粉体市场上的国产造粒粉体虽然价格低廉，但性能与进口造粒粉体有较大的差距，难以满足制备高性能氧化锆陶瓷产品的要求。而进口造粒粉体虽性能较好，但价格却是国产造粒粉体的数倍，在批量生产中会大大提高生产成本，不利于相关产品的大规模推广和应用。本文以国产氧化锆粉体为原料，对其进行表面改性处理，以期在降低生产成本的同时，得到性能接近进口氧化锆造粒粉体的国产粉体。本文采用的表面改性处理工艺包括磨细和喷雾造粒两个步骤。国产氧化锆粉体多数是共沉淀法制成，粉体中有较多的硬团聚，不利于后期的成型和烧结。所以需要先通过磨细打开粉体的硬团聚，将粉体的粒度降到0.2μm以下。再以磨细后的粉体为原料，加入不同种类的粘结剂和增塑剂配制成浆料，对其进行喷雾造粒，得到不同组的造粒粉做对比实验。然后以不同组的造粒粉为原料，对其进行成型和烧结。最后测量烧结体的致密度、抗弯强度、相组成，并用扫描电子显微镜观察其断面形貌，比较喷雾造粒中不同组塑化剂的优劣。最终发现加入PVP和PEG分别做粘结剂和增塑剂的造粒粉体具有最优的性能，在1450℃无压烧结后致密度达到了99.67%，接近进口造粒粉的致密度。另外其抗弯强度也比造粒前的粉体抗弯强度略有提高，达到了降低成本的同时，提高造粒粉的性能指标的目标。同时，实验中使用的生产工艺，如卧式搅拌磨磨细、喷雾造粒机造粒、干法成型和无压烧结都是大规模生产中常用的方法，所以本文的实验结果对于实际生产中应用具有很好的借鉴意义。更多还原

【Abstract】 Zirconia has been widely used to produce functional ceramics and structuralceramics for its excellent properties, such as high strength, high hardness, fine heatresistance, fine corrosion resistance, insulation at normal temperature and conductivityat high temperature. As a result, zirconia powder with high performance at low cost isvery popular in the market. At present, although domestic zirconia powder isinexpensive, its performance is poor and can’t meet the requirements to produce highperformance zirconia ceramic products. Imported zirconia granulated powders can meetthe high requirements but is much more expensive than domestic powder, whichprevents it from being wildly used.In this article, we use domestic zirconia powder as raw materials and modify thesurface of it. In this way, we can improve the performance of domestic powder and atthe same time lower the production costs of it. In this article, surface modificationincludes milling and spray granulation. Domestic zirconia powder is mostly obtained bycoprecipitation method，so there is more hard agglomeration in it, which is unfavorablefor pressing and sintering. So it is necessary to milling the powder to reduce the particlesize to less than200nm. Then add different binders and plasticizers to the milledpowder and spray granulation with it. We press the different groups of granulatedpowder and sinter them in the same condition. Finally, we test the relative density,bending strength and phase composition of the sintered bodies and observe themorphology of the fracture part.The result shows that the spray granulation powder to which is added PVP andPEG performs the best. The relative density of its sintered body at1450℃reaches99.67%approaching that of imported powders and its bending strength is also higherthan raw powder. So we achieve the goal and the method can be directly used inproduction.更多还原