Synthesis of nano-AlN powders from Al wire by arc plasma at atmospheric pressure

We present a simple and effective method for synthesis of high-purity nano-AlN powders by arc-discharge plasma at atmospheric pressure, with an Al wire used as the electrodes and N-2 or mixture of N-2 and H-2 used as the plasma working gas. The effects of the N-2 flow rate and addition of H-2 to the N-2 plasma on the compositions of the obtained powders were investigated. The results show that the increase in the working-gas flow rate improved the purity of AlN in the product and that a small amount of H-2 addition to the N-2 plasma significantly increased the yield of as-synthesized powders. Based on characterizations of the as-synthesized particles and Al wire surface before and after the plasma process, possible formation processes of the obtained micro- and nanoparticles were analyzed.