The study of sliding contact in railgun with metal armature

An experimental technique for the study of the current distribution in the rails and a moving metal armature is developed. The work was carried out on a special experimental railgun with a capacitor power supply. The set of small dB/dt probes as well as wire contact probes were arranged in close vicinity of the rail and armature contact surface. For interpretation of dB/dt measurements, a computation technique and program of restoration of current density distribution along the armature were developed. The size and the location of the current concentration zone in the contact area were obtained for several combinations of rail and armature materials; bronze and copper rails, Al and Ti alloy armature. Teats on a stationary armature with resistive stainless steel and graphite layers were also made to estimate the influence of the layer material resistivity on the current distribution.