Diamond-Like Carbon as a Novel Coating Solution for Wear and Corrosion in M197 Gatling Gun Systems

DLC coatings are amorphous nanocomposites that are primarily composed of sp3 (diamond-like) and sp2 (graphite-like) carbon structures that can be enhanced through the addition of hydrogen and metal dopants (Si, Cr, W, etc.) to modify their properties. IBC has developed a range of self-lubricating DLC coatings for many different applications and environmental conditions. These coatings provide very low friction and high durability without conventional lubrication.IBC’s DLC coatings can be applied via two different vacuum plasma processes – these are the Physical Vapor Deposition (PVD) process and the Plasma Assisted Chemical Vapor Deposition (PACVD) process. The PACVD DLC coatings typically have a hardness of 1000-2000 HV, a deposition temperature of <900°F, and a maximum thickness of 30 microns. The PVD DLC coatings have a higher maximum hardness and a very low deposition temperature of <200°F, but they are limited in thickness and corrosion resistance.  Another important consideration is that the PACVD process is non-line-of-sight, allowing for uniform coatings with no movement or manipulation of complex parts. Lastly, IBC’s PACVD systems can apply Plasma Nitriding and DLC coatings in a single batch, called a “duplex” process. For these reasons, the PACVD technology was chosen for this gun application.