液相沉淀法制备ZrO_2/Al_2O_3纳米复合粉体

PREPARATION OF ZrO_(2)/Al_(2)O_(3 ) COMPOSITE NANOPOWDER BY LIQUID PHASE PRECIPITATION METHOD

以NH4Al(SO4)2·12H2O,ZrOCl2·8H2O,Y(NO)3为原材料,用NH4HCO3作沉淀剂,控制滴定速度小于5mL/min,采用液相沉淀 法制备了超细3YZrO2/Al2O3前驱体。前驱体为分散的碱式碳酸盐,在1200℃煅烧得到了分散性良好,平均粒径为20nm的tZrO2和α Al2O3两相分布均匀的纳米复合粉体。X射线衍射分析显示:前驱体在煅烧过程中无中间相γAl2O3,θAl2O3生成。所制备的粉体具有高 的烧结活性。在1450℃烧结后烧结体相对致密度可达97.4%。

Using pure NH4Al(SO4)2&middot12H2O, ZrOCl2&middot8H2O and Y(NO)3 as starting materials and NH4HCO3 solution as precipitant agent, the ultra fine 3Y-ZrO2/Al2O3 precursor was prepared by the liquid-phase precipitation method, controlling the dripping speed below 5 mL/min. Zirconia/alumina composite nanopowder with good dispersibility and average panicle size of 20 nm was obtained by calcining the precursor at 1200°C. X-ray diffraction patterns show that no γ- Al2O3and θ-Al2O3 were formed during calcination. The resultant powder has an excellent sinterability and the relative density of samples obtained reaches up to 97% after sintering at 1450°C.