Electric Explosion Of High-quality Metal Nanopowder Prepared By The Treatment Process

Nanosized metallic powders are attractive for many potentailapplications. Although there are several methods capable of producingnanosized metallic powders, the seemly inevitably agglomerationhindering their might applications. Among those effectual approaches,passivation treatment appears to be the one of promise to prevent Nanparticles agglomeration.Electrical explosion method is a novel physical method to prepareultra-fine powders. In this research, nanosized metallic powders wereprepared by electrical explosion method and the mechanisms associatingwith it were studied thoroughly. The morphology, microstructures andsize distribution of the particles were investigated by XRD, scanningelectron microscope (SEM) and transmission electron microscope (TEM)respectively. In addition, we have investigated the effective ways ofpassivation according to the mechanism of agglomeration, and developeda successive technique for powders preparation, storage, transportationand utilization. As the result we have established an industrial tradestandard for nanosized metallic powders. The major results of this workare shown as the following.(1) Nanosized powders of many metallic materials, especiallythose of high melting points and those alloys with large difference inmelting points can be prepared by electrical explosion method.(2) The powders are single phased crystals of high purity and theyield is adequate to meet the demand of commercialization.(3) Cooling temperature and protective gas have great influence onparticle size and shape. By adjusting individual processing parameters,we can prepare nanosized metallic powders with controllable shape andsize distribution. For instance, for spherical powders, the particle sizeranges from 30～140 nm with an average of 80nm; and for irregularpowders, the particle size changes from 30～50 nm with an average of 40nm.(4) We have developed an effective passivation method capable ofpreventing powders agglomeration which is required for storage andtransport.