Materials characterization of railgun erosion phenomena

This paper describes the observations of aluminum projectile (or armature) tribomaterial deposition onto copper (stator) conducting rails in an experimental solid-armature railgun system, by optical, and scanning and transmission electron microscopy. The extreme deformation at the aluminum/copper interface creates a solid-state flow regime by dynamic recrystallization which also leads to the erosion-product deposition. Melting of the low-temperature aluminum deposit also contributes to the rail damage and degradation of electromagnetic behavior. The creation of nano-grains by dynamic recrystallization allows for mixing at the aluminum/copper interface, and there is no evidence for traditional alloying.