不添加烧结助剂制备透明的Y_2O_3陶瓷

Fabrication of transparent yttria ceramics using precipitation derived nanopowder

以Y2O3粗粉、碳酸氢铵、硝酸和氨水为原料,通过沉淀法制备了Y2O3纳米粉体.发现沉淀工艺和煅烧温度显著影响Y2O3纳米粉的颗粒大小和尺寸分布,从而影响烧结体的密度和透光性.用X射线衍射分析仪、透射电镜、图像分析仪等研究发现,pH=8时制得的沉淀先驱物经1000℃煅烧,可得到粒度为33 nm,近球形,分散性好,尺寸分布窄的Y2O3粉体.该粉体不加任何添加剂,在1700℃真空烧结4 h可得到透明Y2O3陶瓷.

Y2O3 nanopowders were synthesized using a chemical precipitation process from coarse yttria Y2O3 powders, ammonium hydro-carbonate, nitric acid and aqueous ammonia. X-ray diffraction (XRD) was used to determine the phase constitution of the yttria powder. Morphology and size of the powders were observed by transmission electron microscope (TEM). Size distribution of the powder was analyzed using Image Analyser. The precipitation processing parameters and calcination temperatures have a significant effect on the particle size and size distribution of the synthesized Y2O3 nanopowder, and thus influence the density and transparency of the sintered ceramics. The Y2O3 nanopowder produced by calcining the precursor (obtained at a pH of 8) at 1000°C is 30 nm in particle diameter, spherical in shape, well dispersed, and narrow in size distribution. This Y2O3 powder can be sintered into transparent body by a vacuum sintering at 1700°C for 4 h without any additive.