作　　者： ; ; ; ; ; ;

机构地区： 华南理工大学材料科学与工程学院特种功能材料教育部重点实验室

出　　处： 《人工晶体学报》 2009年第3期782-787,共6页

摘　　要： 以NH4Al（SO4）2与NH4HCO3为原料,采用共沉淀法制备出前驱物碳酸铝铵（AACH）,并煅烧得到超细α-Al2O3粉末。研究了pH值、滴加速度及醇水混合溶剂等因素对反应产物的影响,并对前驱物AACH的高温相变过程和α-Al2O3籽晶对θ-Al2O3→α-Al2O3相变的影响进行了分析。利用XRD、TEM和BET等对粉体的性能进行表征。结果表明：在醇水混合溶剂中控制反应体系的pH值为9-10,将硫酸铝铵溶液以〈18 mL/min的速度滴入碳酸氢铵溶液,可合成颗粒细小、粒度分布均匀且分散性优异的AACH前驱物。不含籽晶的AACH煅烧时α相完全转化温度为1150℃,获得α-Al2O3粒径约为100 nm,而α-Al2O3籽晶的加入可将完全转变温度降至1050℃,获得的α-Al2O3粒径约为70 nm。 Ammonium aluminum carbonate hydroxide （AACH） was synthesized as the precursor by the precipitation reaction of ammonium aluminum sulfate and ammonium hydro-carbonate. Then the precursor was calcined to get ultrafine α-Al2O3 powder. The effects of pH value, adding rate and a mixed solvent of ethanol-water on the reaction product of AACH were researched. Phase transformation of AACH upon heating and effect of α-Al2O3 seed on the transformation kinetics were also analyzed. The structural properties of powders were characterized by XRD, TEM and BET. The results show that the AACH nanoparticles with uniform particle size and well-distribution can be synthesized in ethanol-water solvent by adding ammonium aluminum sulfate solution to ammonium hydro-carbonate solution with a rate less than 18 mL/min and controlling the pH value between 9 and 10. For the sample without seed, the temperature of transforming completely into α-Al2O3 is 1150 ~C, and particle size of the α-Al2O3 powder is about 100 rim. By adding α-Al2O3 seed, the temperature can be reduced to 1050 ℃, and particle size of α-Al2O3 powder is about 70 nm.

关 键 词： 碳酸铝铵 醇水溶剂 籽晶 相变 超细粉

领　　域： [冶金工程] [冶金工程]