Cold sprayed refractory metals for chrome reduction in gun barrel liners

• Cold Spray technology enables dense, high strength refractory metal deposits.
• Cold Spray can consolidate donor tubes for explosively clad gun barrel liners.
• Additively manufactured donor tubes reduce machining operations and material waste.

Modern gun barrel technology faces a number of challenges related to the use of chrome-plated steel at the interior bore surface. The amount of allowable chrome has been significantly reduced due to environmental, health, and safety concerns. Furthermore, current munitions and propellants lead to erosion and condemnation of gun barrels well before their 10,000 round expected lifetime. This has precipitated a search for longer-lasting bore liners, such as refractory metals deposited by explosive bonding. The cost and difficulty associated with shaping these materials have made them impractical choices to date. Gas Dynamic Cold Spray consolidation of refractory metals and alloys was selected as an alternative to extrusion for additive manufacture of donor tubes. Tantalum–10 tungsten alloy donor tubes have been produced by cold spray and tested for compatibility with the cladding process. A 1-meter (3-foot) long tube was produced to test scalability.