摘要: 对喷雾干燥和不同温度热处理后Al₂O₃/TiO₂/SiO₂纳米团聚体粉 末的流动性、松装密度及振实密度进行了测试，对喷雾干燥后的粉末进 行了热重－差热分析，通过扫描电镜观察了粉末颗粒形貌和大小，采用 X 射线衍射分析了不同温度热处理后粉末的相组成，并对粉末的综合性 能进行了比较。实验结果表明：在1 000～1 450℃热处理后的Al₂O₃/TiO₂/ SiO₂ 纳米团聚体粉末颗粒仍近似球形，粒径在 10～100 μ m 之间。随着 热处理温度升高，纳米团聚体大颗粒表面发生塌陷，大颗粒之间发生连 接，大颗粒内部纳米颗粒明显长大。低于 1 250℃热处理后的粉末流动 性好，振实密度高，适于等离子体喷涂制备纳米结构涂层。 

关键词：氧化铝；纳米结构；团聚体粉末；热处理温度

Abstract：In this study，free holding density，tap density and flow ability of spray-dried and heat-treated agglomerated Al₂O₃/TiO₂/SiO₂ nanocrystalline powder were measured. Thermogravimetric analysis and differential thermal analysis of the spray-dried powders were conducted. Scanning electron mi croscopy and optical microscopy were used to examine the morphology and particle size of the powders. X-ray diffraction was used to analyze the phase constituent of the powders. The over-all properties of the powders were compared. Experimental results show that the large agglomerated particles heat-treated at a temperature in the range of 1 000～1 450℃ have the size of 10～100μm and still have the nearly spheric shape. With the increase of heat treatment temperature, the surface of the large agglomerated particles collapsed， the large particles began to connect with each other， and the nanocrystalline particles grew up significantly. Such powders with good flowability and high tap density，after heat treatment below 1 250 ℃，are suitable for thermal spraying in the deposition of nanostructured coatings. 

Keywords:alumina/titania/silica；nanocrystalline；agglomerated powder； heat treatment temperature