( 1. 北京科技大学 材料科学与工程学院，北京 100083；
2. 天津理工大学 材料科学与工程学院， 天津 300191；
3. 中南大学 粉末冶金国家重点实验室， 长沙 410083)
摘 要: 以硝酸铝和碳黑为原料， 利用化学沉淀法制备出混合均匀的Al2O3+C前驱物，并以该前驱物为原料采用碳热还原法制备了AlN粉末。 研究了氮化反应温度、 pH值、 表面活性剂、 溶液浓度、 氮气流量和碳铝比等工艺参数对氮化反应的影响， 得出的最佳工艺参数分别为: 以0.4 mol/L的硝酸铝溶液和比表面积为156 m2/g的碳黑为原料， 控制原料中碳铝比为3∶1， 添加适量的硬脂酸（SA）和聚乙二醇（PEG）作为表面活性剂， 控制沉淀过程中pH=9， 通过共沉淀工艺得到分散性好、团聚程度小的前驱物， 并将此前驱物在常压和氮气流量为5 L/min的条件下于1 550 ℃煅烧4 h，最后将反应产物在650 ℃的空气中除碳4 h， 制备出氮含量为33.20%， 氧含量为0.98%， 比表面积为4.26 m2/g的AlN粉末。
关键字: AlN粉末； 沉淀前驱物； 碳热还原
precipitated precursor
（ 1. School of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China;
2. School of Materials Science and Engineering,
Tianjin University of Technology, Tianjin 300191, China;
3. State Key Laboratory of Powder Metallurgy,
Central South University, Changsha 410083, China）
Abstract: A homogenous mixture precursor of Al2O3+C was prepared by the chemical precipitation method and AlN powders were fabricated by carbon thermal reduction nitridation of the precipitated precursor. The effect factors on the nitridation conditions and the properties of AlN powders, including nitridation temperature, pH value, surface active agent, solution concentration, N2 flow rate and molar ratio of carbon to aluminum, were investigated. An optimal process was obtained through synthesizing fine and pure AlN powders. Firstly, a homogenous and good dispersion precursor was prepared by the precipitation process using 0.4 mol/L Al(NO3)3 solution and 156 m2/g carbon black as materials at pH=9, the molar ratio of carbon to aluminum was controlled to 3∶1 and a certain amount of stearic acid and ethylene glycol was added as surface active agents. Then, the precursor was heated at 1 550 ℃ for 4 h under common pressure at N2 flow rate of 5 L/min. Finally, AlN powders with nitrogen content of 33.20%, oxygen content of 0.98%, specific surface area of 4.26 m2/g were produced after decarbonization of the nitridation products in air for 4 h at 650 ℃.
Key words: AlN powders; precipitated precursor; carbothermal reduction
