Barrel Coating and Liners for Extended Barrel Life

"Gun barrel erosion is due to thermo-chemical reactions. Modern propellants are highly corrosive and burn at ever-higher temperatures. Refractory metals have been demonstrated to resist thermo-chemical reactions better than any other available coating orliner. The problem has been in keeping the material in place under extreme firing conditions.TPL successfully demonstrated explosively clad, tantalum-lined gun barrels under live-fire conditions in 2001, using the extremely hot burning M919 ammunition. In a smoothbore barrel, over 1300 rounds were successfully fired, compared to the baselinetest, <300 rounds, when the barrel was condemned. These liners were made from pure tantalum, which is a relatively soft metal, which may have problems resisting projectile spin up or the balloting experienced with large bore gun tubes.TPL proposes to characterize alternative refractory metals and alloys for use in large caliber rifled gun tubes. TPL will fabricate tubing of the selected materials for cladding in short simulated gun tube sections. These sections will be cut intospecimens for evaluation of bond quality, bond strength, and fabricated into conforming parts for small-scale erosion tests. Through this effort TPL will identify a material that has both erosion and wear resistance, and one that is available insufficient quantities for use in gun barrel manufacturing.TPL and the principle investigator have unique expertise in explosive