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采用液相共沉淀法和机械混合法成功制备了阴极用(nBaO:nCaO:nAl2O3=6:1:2)铝酸盐,并研究了烧结温度对612铝酸盐的影响,同时探讨其烧结机制以及烧结过程中物相之间存在的化学反应。采用扫描电镜、能谱仪、X射线衍射仪和激光粒度分析仪对铝酸盐形貌、粒度分布以及物相变化进行了研究。结果表明:采用液相共沉淀法成功制备出亚微米粒径的准球形前驱粉末,D(n,50)值仅为815 nm。前驱粉末经过高温烧结(1500℃b)后,得到了晶化程度高,主晶相为Ba5CaAl4O12的612铝酸盐,浸渍钡钨阴极后,1100℃b下的发射电流密度达15.56 A/cm2,蒸发速率仅为14.5 nm/h。
The cathodes (nBaO: nCaO: nAl2O3 = 6: 1: 2) aluminate were successfully prepared by liquid coprecipitation and mechanical mixing, and the effects of sintering temperature on 612 aluminate were investigated. Meanwhile, the sintering mechanism As well as the chemical reaction existing between the phases in the sintering process. The morphology, size distribution and phase change of aluminate were investigated by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and laser particle size analyzer. The results show that the quasi - spherical precursor powder with submicron particle diameter is successfully prepared by liquid coprecipitation method, and the D (n, 50) value is only 815 nm. After the precursor powder sintered at high temperature (1500 ℃ b), the 612 aluminate with high degree of crystallization and the main crystal phase of Ba5CaAl4O12 was obtained. The emission current density at 1100 ℃ b reached 15.56 A / cm2 after impregnation with barium tungsten cathode, The evaporation rate is only 14.5 nm / h.