Advanced Materials/Coatings for Gun Barrels

The application of advanced barrel coatings to provide extended erosion and wear life with high performance ammunition for existing and proposed weapons systems has been limited by the available process technologies capable of applying the required/desired coatings. Electroplating, Chemical Vapor Deposition (CVD), and Physical Vapor Deposition (PVD) have all been attempted with varying degrees of success. Desired coating materials are best applied using PVD, however PVD has suffered from geometric constraints due to a line-of-sight requirement from target to substrate. SURFACE SOLUTIONS (SSI) has developed a new form of PVD deposition, DC Linear Magnetron Sputtering (LMS), capable of uniform deposition inside a gun barrel with a length to diameter ratio exceeding 100 : 1. SSI believes that LMS will be capable of uniformly depositing high-temperature, corrosion resistant materials such as tantalum, alloys of tantalum, molybdenum, niobium, etc. LMS is a line-of-sight PVD process whereby the target(coating material) is tubular and is aligned coazially with the substrate (gun barrel). Sputtering occurs radially and uniformly down the entire lingth of the target and requires no external magnets to contain the plasma. The required uniform magnetic field is generated electrically and is the basis of SSI's LMS process.