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1000～1450℃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10～100μm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1250℃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。
tIn 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,t hes urface oft hel argea gglomerated 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.
出处
《中国粉体技术》
CAS
2005年第2期24-28,共5页
China Powder Science and Technology
基金
人事部回国人员择优发展项目资助
关键词
氧化铝
纳米结构
团聚体粉末
热处理温度
alumina/titania/silica
nanocrystalline
agglomerated powder
heat treatment temperature
