Medium Caliber Gun Barrel Bore Coatings

Electroplated hard chrome coatings are widely used as protective coatings on the gun barrel bores. In addition to the serious health risks that are associated with hard chrome plating, these coatings also suffer from some significant material property drawbacks, including an intrinsic brittleness and porosity/microcracks, which often lead to premature coating failure. In Phase I, the feasibility of producing a fully dense, non-micro-cracked Nanostructured cobalt–refractory metal alloy with co-deposited hard ceramic particles was demonstrated. The Nanostructured coating was found to have wear resistance equal to that of hard chrome coatings, but did not suffer from the same micro-cracked structure that chrome possesses, even after thermal cycling to 1832°F. The Phase II program proposed herein will build upon the success of Phase I. The specific objectives of the program are to: (1) optimize the protective properties and develop the tooling needed to scale up the nanostructured composite coating technology developed in Phase I to coat the bores of full sized medium caliber gun barrels, (2) perform the required simulated (Pulse Laser and Vented combustion chamber) and actual field testing to fully demonstrate and validate the technology, and (3) define all critical technical parameters in a thorough process specification to allow the technology to proceed to facility demonstration/validation activities.