共沉淀法制备t-ZrO_2/Al_2O_3纳米复合粉体研究

Preparation of t-ZrO_2/Al_2O_3 Nanometer Composite Powder via Coprecipitation Method

用NH4Al（SO4）2·12H2O、ZrOCl2·8H2O和NH4HCO3为原料，采用共沉淀法合成了t—ZrO2／Al2O3，纳米复合粉体，前驱体的制备温度以45℃为宜。反应物NH4HCO3／（Zr＋Al）摩尔比对反应中锆的沉淀率影响显著．前驱体经1100℃焙烧1h后出现t—ZrO2和γ—Al2O3的宽化衍射峰,t—ZrO2较均匀地分散于氧化铝中，两相晶粒大小都在10—20nm之间．样品进一步加热到1200℃时α—Al2O3相迅速生成并伴有部分晶粒融合发生．

With NH4Al（SO4）2·12H2O, ZrOCl2·8H2O and NH4 HCO3 as raw materials, the nanometer composite powder t - ZrO2/Al2O3 was fabricated by means of coprecipitafion. The suitable preparation temperature of precursor was 45℃. The molar ratios of NH4HCO3 / （ Zr ＋ A1） had a notable impact on the precipitation rates of zireonium in reaction. After precursor was calcined at 1 100 ℃ for 1 hour, the broaden diffraction peaks oft - ZrO2 and γ - Al2O3 appeared, t - ZrO2 was relatively uniformly dispersed in alumina, and the grain sizes of both phases were between 10 - 20 nm. Sample further heated to 1 200 ℃, α - Al2O3 phase rapidly formed and accompanied the blend of erystallites in part.