Investigation of Tungsten, Copper, and Silver Alloys with Indium at the Rail-Armature Interface on a Railgun Test Bench

Authors: D. Gillich; W. Maier; MILITARY ACADEMY WEST POINT NY DEPT OFPHYSICS

Abstract:

With the advent of electrically propelled ships, the Navy is now considering the use of electric power to launch projectiles in support of maritime land attack. Bore wear is one of the most significant challenges for a naval railgun program. The interface between the armature and rails is the most stressed point of a railgun because it transitions to liquid under high current densities. This liquid interface causes rail and projectile material to redistribute unevenly thereby produces rail degradation. Various combinations of tungsten, copper, and silver alloys were tested for rail and armature materials to determine which combination resulted in minimum damage during firing. The least degradation was observed with a silver-tungsten projectile and copper-tungsten rail: 10% loss in projectile mass for a current density of approximately 86 kA/sq cm. Indium at the interface protected the rails and projectile from damage at current densities under 21.5 kA/sq cm.

Limitations:

APPROVED FOR PUBLIC RELEASE