Energy dissipation and efficiency of exploding stainless steel wires of various lengths and diameters

Abstract

Electrical exploding wires have found many applications in industry and research. Some of the most promising applications include high-speed sheet metal forming and explosive welding. Most research to date has been conducted using thin highly conductive, pure metal wires at relatively low energies. In contrast, experimental trials are performed in air, on relatively thick AISI 304 stainless steel wires with diameters 600–800 µm and lengths ranging from 40 to 160 mm. The test wire produces circuit damping in a series RLC circuit with C = 150 µF and L = 4.36 µH, which yields a maximum theoretical discharge energy of 2.7 kJ at 6 kV. The energy absorbed in the wire and the wire plasma respectively, is calculated to determine the fraction of absorbed energy, i.e. the energy transfer efficiency, for each case and the optimum wire dimensions for the circuit. Longer wires attain a lower action integral and absorb more energy with respect to short wires resulting in a higher energy transfer efficiency to the wire. Thicker wires attain a lower final action integral despite lower initial resistance and absorb more energy with respect to thin wires resulting in a higher energy transfer efficiency to the wire. The total efficiency of dissipated energy in the wire is analysed depending on the wire length and diameter, together with an introduction of the time-averaged wire resistance.