Preparation of metal oxide nanopowders by the spark discharge method

Experiments were carried out to obtain nanopowders of metal oxides Al, Fe, Cu and Ti by the spark discharge method. To obtain nanopowders, an electrode system consisting of two series-connected discharge gaps was used. The dependences of the powder output, dispersion and phase composition of the powders on the energy of the capacitive storage are obtained. It is shown experimentally that the powder output is determined by the energy stored by the capacitive storage and the erosion resistance of the electrode material. Upon production of the Al oxide nanopowder, an output equal to 4 µg/pulse was achieved. The obtained oxide nanopowders were analyzed by XRD, BET, and TEM. It’s shown that the produced nanopowders are agglomerates of small primary particles. The bulk of the powder is composed by small less than 20 nm particles. The synthesized particles have a crystal structure. The main crystalline phases formed in small primary particles are given.