摘要
高性能的复合粉体是制备纳米复相陶瓷材料的关键.采用醇-水溶液加热法结合共沉淀过程制备纳米Al2O3/ZrO2复合粉体,研究了不同沉淀剂对粉体团聚的影响,利用透射电镜、X射线衍射、热重-差热分析、比表面积测定等技术对获得的纳米复合粉体进行了表征.结果表明:采用NH4HCO3作为沉淀剂可以得到几乎无团聚的碱式碳酸盐前驱物,该前驱物在煅烧过程中的物相变化显示四方相氧化锆(t ZrO2)的形成温度大幅度地提高,同时在较低温度下生成了α Al2O3,在1100℃转变为t ZrO2相和α Al2O3相;粉体中两相颗粒分散良好、粒径一致、无硬团聚,其平均粒径为15～20nm,比表面积为69 5m2·g-1.
Synthesis of high performance composite powders is the key to prepare nanocomposite ceramics. The final powders of Al_2O_3/ZrO_2 with excellent chemical homogeneity were synthesized by heating of ethanol-aqueous salt solutions combined co-precipitation method. The effect of the precipitant on the agglomeration was researched. The powders are identified by TEM, XRD, BET, TG and DTA. The results demonstrate that the using of ammonium hydrogen carbonate produced a basic carbonate precursor that was loosely agglomerated and the resultant powders showed good dispersity and excellent sinterability. The formation temperature of the tetragonal zirconia crystals increases greatly, while the converted temperature of α-Al_2O_3 phase decreases sharply. The powders convert to t-ZrO_2 phase and α-Al_2O_3 phase completely at 1 100 ℃. The powders have good dispersion, uniform grain size and no hard agglomeration. Nanoscaled Al_2O_3/ZrO_2 powders with particle size of 15～20 nm and specific surface area of 69.5 m^2·g^(-1) can be obtained.
出处
《材料科学与工艺》
EI
CAS
CSCD
2004年第1期20-23,28,共5页
Materials Science and Technology
基金
国家自然科学基金资助项目(50375037).
