Production of carbon-coated aluminium nanopowders in pulsed microarc discharge

A new technique of metal nanopowder production and in situ coating using a microarc discharge is proposed. The feasibility of this method is demonstrated and preliminary results are presented. The microarc discharge was operated at 1 atm in both pure Ar and natural gas environments. Respectively, aluminium nanoparticles without and with ∼1 nm thick carbon surface coating were obtained. The morphology and structures of the nanoparticles were studied using a transmission electron microscope (TEM), and size distribution of the coated particles was determined from the TEM image analyses. It was found that the sizes of the produced carbon-coated aluminium particles were well described by a lognormal distribution with the geometrical mean size of 22.7 nm and standard deviation of 1.35.