Experimental study of slow electrical explosion of thin titanium wires

The paper presents results of experimental studies of a slow (during 50÷100 μs) electric explosion of thin titanium wires in argon and air media. In that explosion wire destruction and its fragmentation are complex processes associated with thermo-mechanical stresses and electromagnetic forces. The explosion was characterized by oscillography and photography. Schlieren photos of the explosion allowed to visualize features of the wire dispersion. It was demonstrated that the nature of wire defragmentation was determined by a specific energy input Q_R. At Q_R ≈1.2÷1. 5 J/mg wire fragmentation occurred with the formation of micron particles (with a diameter of 50÷150 μm). At Q_R≈2.5÷2.8 J/mg forming of not only micron particles but also titanium nano powders due to electric arc ignition and extreme wire evaporation with the following non-equilibrium condensation. In the mode of high specific energy inputs generation of shock waves took place. The measured wave velocities reached of 700÷750 m/s. The manufactured titanium particles had purity of 96.65÷99.01 % as for raw wires. (paper)