Wear of conductors in railguns: metallurgical aspects

The wear debris generated by an aluminum alloy armature sliding on copper rails was studied experimentally. The experimental parameters were set to maximize armature velocity. Preliminary rail and armature wear observations were documented as part of a database for solid armature development. A variety of debris collection and characterization approaches were used. Both in-bore debris and muzzle-exit debris were collected for size and chemical analysis. Debris constituents were copper-rich, and the compound Cu₉Al₄ was observed in the splat-quenched muzzle debris. The approach and method are detailed to indicate the potential of wear studies in defining the activity at the sliding interface. Some implications of rail surface roughening for zero wear measurements are also discussed, and the adoption of wear mechanism maps is proposed