The production of nanosized powders occurs due to the transmission of a high-density current pulse through a piece of metal wire (foil), under the action of which the wire is destroyed into finest particles and vapor. Disintegrating at high speed, the products of destruction quickly cool down and a hig-dispersive powder is formed.
Depending on the kind of gas surrounding the broken wire, it is possible to obtain powders of metals, alloys, powders of chemical compounds or powders of blend compositions. In this case, individual particles are compositional
The powder dispersion, particle structure and other properties are determined by the parameters of the discharge circuit, the material and the geometric dimensions of the wire (foil) and the characteristics of the gas medium in which the explosion is made.
The technological process is carried out in an enclosed volume, without the use of harmful chemicals and with a very low consumption of inert gases. Moreover, the gas consumption is mainly related not to the production of the powder, but to its transportation, packaging and other subsequent operations.
Developed power during the explosion, W: 106-1013
Cooling rate of the explosion product, deg/c: 105-109
The possibility of fine-tuning of the energy input into a conductor.
Technology of electroexplosive production of advanced powders:
A storage condenser is charged from the high-voltage power source. The wire feed mechanism provides an automatic installation of an exploded section wire between two electrodes. As soon as a section wire takes a predetermined position, the switch is turned on, the accumulator is discharged to this section wire, and it explodes.
Newly formed powder is collected in a storage tank, passivated and fed for further processing. The chamber volume is vacuumed and then filled with a gas atmosphere. These functions are performed by the gas supply system. As a gas atmosphere, inert gases, mainly argon, are used. In some cases, use of hydrogen, nitrogen or a mixture of gases, for example, argon + oxygen is to be preferred.
All the elements of the plant are assembled in two blocks: an electric energy pulse generator and a module.
The figure shows the stages of a conductor electrical explosion (CEE),
which were taken with the help of the high-speed photo-recording device (PRD).