The influence of the rail material on the multishot performance of the rapid fire railgun (RAFIRA)

The Rapid Fire Railgun (Rafira), a unique railgun which can be operated in multishot mode is well suited for the study of the influence of different rail materials on velocity and electrical contact of the armature and/or the wear of different rail materials. That is why we performed experiments with Rafira operated in multi shot mode (fire rate of 50 Hz), using different rail materials (CuCr and Dural) and varying shot energy. For these experiments, the shot energy for Rafira was raised, for the first time, up to the maximum energy at disposal of 1.45 MJ per shot with armature masses of over 100 g. In this way, we were able to show that the influence of the rail material depends on the applied shot energy: for low shot energies (<; 1MJ), CuCr rails show better results in terms of velocities and exit times of the armatures. This effect vanishes for high shot energies (> 1MJ). Whereas in terms of electrical contact, Dural rails show both less erosion and the capability to maintain a solid sliding contact until shot out for all energies applied.