Electrical explosion at reduced gas pressure

The electrical explosion of wires is used as a method for studying the behavior of metal under the conditions of fast Joule heating, for instance, in investigation of an explosive electron emission. On the other hand, the exploding wire method is of great interest of ultra-fine powder production. The electrical explosion of iron, aluminum, titanium, platinum, indium, cobalt and copper wires has been investigated in nitrogen, noble gases and air at pressures from 0.01 to 1 atm. Particle sizes were determined using transmission electron microscopy and low-temperature adsorption method. The phase composition was determined by X-ray and electron diffraction methods. As the density of the surrounding gas is increased, the particle size decreases. The minimum of gas pressure is shown to be similar to the Paschen curves and depends on exploding metal. To produce powders of a pure metal, it have been proposed to use nitrogen, which is chemically inert at the lower pressure and has a higher electric strength in comparison with noble gases.