Zhao Ke, Chao Yong-lie, Yang Zheng
Department of Prosthodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2003 Sep;38(5):384-6.
To prepare zirconia toughened nano-composite alumina ceramic powder for dental application. Physical and chemical property of the prepared material were tested, and the effect of development technology on composite powder was also studied in this study.
Nano-composite alumina powder was prepared by surface-induced precipitation method. The effect of pH value and dispersing agent content on volume of alumina suspension sediment was recorded. The effect of ultrasonic time on agglomeration was measured also. X ray diffraction (XRD) was used to analyze powder phase before and after the stabilizer was added. Scanning electronic microscope (SEM) was applied for characterizing the specimen.
The dispersion was better at pH=9 and wt (dispersing agent) = 0.2% approximately 0.3%. Selecting proper ultrasonic time can decrease the agglomeration of powders and lower the average particle size. XRD analysis indicated that the phase composition of the prepared nano-composite ceramic powder was shown as alpha-Al2O3, t-ZrO2 and a small amount of m-ZrO2 after the addition of stabilizer. Through SEM observation, nanometer-sized ZrO2 particles (80 approximately 100 nm) were uniformly located on the surface of submicrometer alumina grains.
By choosing appropriate preparation method, weakly agglomerated powders with fine particle size can be obtained. The zirconia part of nano-composite powder was transmitted to partially stabled zirconia after the use of stabilizer.
制备用于牙科的氧化锆增韧纳米复合氧化铝陶瓷粉末。对所制备材料的物理和化学性质进行测试，并研究其制备工艺对复合粉末的影响。
采用表面诱导沉淀法制备纳米复合氧化铝粉末。记录pH值和分散剂含量对氧化铝悬浮液沉淀体积的影响。同时测定超声时间对团聚的影响。添加稳定剂前后，用X射线衍射（XRD）分析粉末相。应用扫描电子显微镜（SEM）对样品进行表征。
在pH = 9且wt（分散剂）约为0.2%至0.3%时分散效果较好。选择合适的超声时间可减少粉末团聚并降低平均粒径。XRD分析表明，添加稳定剂后，所制备的纳米复合陶瓷粉末的相组成为α-Al2O3、t-ZrO2和少量m-ZrO2。通过SEM观察，纳米尺寸的ZrO2颗粒（80至100nm）均匀地位于亚微米级氧化铝颗粒表面。
通过选择合适的制备方法，可获得粒径细小、团聚较弱的粉末。使用稳定剂后，纳米复合粉末中的氧化锆部分转变为部分稳定的氧化锆。
