酸洗提纯AlN粉体的研究

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(H3 PO4)、硝酸(HNO3)、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HNO3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Al2O3的反应有效去除氧杂质.HF/HNO3酸液的适宜配比为HF:HNO3=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%.

Purification of AlN Powders by Acid-Pickling

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 (H3 PO4 ),nitric acid (HNO3 ),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 HNO3 has a better purification effect,especially on removing Na,W and Fe impurities. In addition,HF could also reduce oxygen impurity by reacting with Al2O3 . The optimum ratio of HF to HNO3 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%.