摘要
研究了共沉淀过程pH值对凝胶热分解后Y_2O_3、MgO部分稳定ZrO_2相组成的影响。采用XRD、Raman光谱,以及高分辨电镜分析了凝胶析晶过程结构的演变规律。认为氧化锆的相组成受凝胶先驱体结构的控制,沉淀过程pH值影响水合氧化锆凝胶的结构,进而影响凝胶热分解后ZrO_2的相组成。近中性和高碱性条件下沉淀的凝胶分别具有类单斜和类四方氧化锆结构。
The effect of pH for coprecipitation of ZrO_2 gel on the crystal phase in the calcined zirconia powder was determined. Fraction of tetragonal ZrO_2 in the powder doped by Y_2O_3 or MgO increases with the increasing of pH value.Monoclinic zirconia is produced from materials precipitated in the near neutral condition, almost pure tetragonal zirconia is obtained in the pH range of 13—14. The structural evolution of ZrO_3 gel during crystallizing process was investigated using XRD, Raman spectrum and electron diffraction technique. It is realized that phase composition of calcined ZrO_2 is controlled by precursor gel structure. The pH of the solution affects the structure of hydrated ZrO_2 gel precipitated from it, and then affects the structure of dehydrated ZrO_2 gel and calcined ZrO_2. Dehydrated ZrO_2 gel precipitated in the near neutral condition and pH value in the range of 13—14 have the monoclinic-like and tetragonal-like structure respectively.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1991年第5期403-408,共6页
Journal of The Chinese Ceramic Society
