酸洗提纯AlN粉体的研究

Purification of AlN Powders by Acid-Pickling

氮化铝(AlN)粉体中的金属杂质与氧化是影响其纯度和性能发挥的主要因素,而酸洗是提纯AlN粉体的有效手段。实验采用磷酸(H_3PO_4)、硝酸(HNO_3)、氢氟酸(HF)和盐酸(HCl)对AlN粉体进行酸洗提纯,主要研究了酸洗过程中酸液的选择与配比对提纯效果的影响。实验结果表明:这四种酸均显著降低了AlN粉体表面的金属杂质含量,而HF和HNO_3的混合酸具有更好的提纯效果,特别能降低其中的Na、W、Fe等金属杂质,而且还可通过HF与Al_2O_3的反应有效去除氧杂质。HF/HNO_3酸液的适宜配比为HF∶HNO_3=2∶1,在该条件下酸洗后的AlN粉体中,金属杂质含量均下降到100 ppm以下,氧含量仅为1.2wt%。

Metal impurity and oxidation are the major factors which affect purity and performance of aluminum nitride（ AlN）. In this paper,AlN powders were purified by acid-pickling using four kinds of inorganic acids,including phosphoric acid（H_3PO_4）,nitric acid（ HNO_3）,hydrofluoric acid（ HF） and hydrochloric acid（ HCl）. The results show that the contents of the metal impurities in the AlN powders could be effectively reduced by acid-pickling. And the mixture of HF and HNO_3 has a better purification effect,especially on removing Na,W and Fe impurities. In addition,HF could also reduce oxygen impurity by reacting with Al_2O_3. The optimum ratio of HF to HNO_3 is determined to be 2∶ 1. Under this condition,the contents of the metal impurities are reduced to less than 100 ppm,and the oxygen content is reduced to 1. 2 wt%.