以Y(NO3)3和NH4HCO3为原料,采用正向滴定法,得到了化学组成为Y2(CO3)3·2H2O的先驱沉淀物。结果发现:时效可使沉淀物的颗粒尺寸和形状发生明显变化,时效48h后,先驱沉淀物形状由球形变为针状;先驱物经水洗-乙醇清洗-丙酮清洗可提高Y2O3粉体的活性;针状先驱物在1100℃下煅烧4h能得到团聚轻的Y2O3粉体,粉体平均粒径约为80nm;所得粉体在1700℃真空烧结4h后,获得了透明Y2O3陶瓷。
A carbonate precipitation process for synthesizing nanocrystalline yttria powder and transparent yttria ceramics was investigated. In this process Y(NO3)3 and NH4HCO3 were ultitized to precipitate a carbonate precursor with chemical composition of Y2 (CO3)3 · 2H2O. It is found that aging has a dramatic effect on the morphology and size of the precipitation precursor. After aging for 48 h, yttrium carbonate with a needlelike structure is formed. Employing distilled water, ethanol, and acetone washing process on the precipitation precursor, sinterability of the yttria powder can be enhanced. Yttria powders with good dispersion and a primary particle diameter of 80 nm are produced by calcining the needlelike precursor at 1 100℃ for 4 h. Transparent yttria ceramics are fabricated by vacuum sintering at 1 700℃ for 4 h.