Synthesis of aluminum nitride powders from a plasma-assisted ball milled precursor through carbothermal reaction

In this paper, aluminum nitride (AlN) powers have been produced with a novel and high efficiency method by thermal annealing at 1100–1600 °C of alumina (Al2O3) powders which were previously ball milled for various time up to 40 h with and without the assistant of dielectric barrier discharge plasma (DBDP). The ball milled Al2O3 powders with DBDP and without DBDP and the corresponding synthesized AlN powers are characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscopy. From the characteristics of the ball milled Al2O3 powders with DBDP and without DBDP, it can be seen that the ball milled Al2O3 powders with DBDP have small spherical structure morphology with very fine particles size and high specific surface area, which result in a higher chemical efficiency and a higher AlN conversion rate at lower thermal temperature. Meanwhile, the synthesized AlN powders can be known as hexagonal AlN with fine crystal morphology and irregular lump-like structure, and have uniform distribution with the average particle size of about between 500 nm and 1000 nm. This provides an important method for fabricating ultra fine powders and synthesizing nitrogen compounds.