钇稳定氧化锆纳米粉体烧结工艺的研究

Research on the Sintering Processing of the Yttria Stabilized Zirconia Nano Powders

实验研究了钇全稳定氧化锆(8YSZ)纳米粉体的烧结工艺,根据阿基米德原理测瓷体密度,通过测定烧结前后瓷片尺寸获得烧结线收缩率,使用扫描电子显微镜观测样品微观形貌,并探讨了纳米粉体烧结的致密化过程,分析了烧结工艺对致密度和晶粒大小的影响,得到了8YSZ纳米粉体合理的烧结工艺为:采用两步烧结,首先升温到1500℃,升温速率为3℃/min,然后降低温度到1450℃,烧结时间为4h。结果显示,采用该工艺,可以得到相对密度98%,晶粒尺寸小于3μm的性能优异的8YSZ瓷体。研究发现,粉体粒度对烧结性能影响较大,纳米粉体比普通粉体具有较低的开始烧结温度,双粒度混合粉体可以进一步提高其烧结性能。

The sintering process of 8%（mole fraction, the same below） yttria stabilized zirconia （SYSZ） nano powders was investigated. The density of 8YSZ ceramics was measured according to Ar- chimedes＇ principle. The line shrinkage was obtained by measuring the size of 8YSZ ceramics before and after sintering. The microstructure of 8YSZ ceramics was observed by SEM. The densification process of the 8YSZ ceramics during sintering was discussed. The influence of the sintering process on the density and grain size was analyzed. The oplimum sintering process of 8YSZ nano powders is adopting two steps sintering which is first heated at 1500℃ and then holding at 1450℃ for 4h. By this process the 8YSZ electrolyte with high relative density（98%） and small grain size（〈3μm） was obtained. In addition to, the influence of the grain size of powder on sintering performance was investigated. The result shows that the start sintering temperature of nano powder is lower than micron powder and adopting powder with bimodal particle sizes is helpful to improve the sintering performance.