EROSIVE WEAR BEHAVIOR OF CHEMICAL VAPOR-DEPOSITED MULTILAYER TUNGSTENCARBIDE COATING

Erosive wear of components by solid particle impingement is a problem faced by many industries. A variety of protective coatings deposited b y thermal spray, physical vapor deposition, and chemical vapor deposit ion techniques have been developed over the years to reduce erosive we ar of components and increase their useful life. These coatings genera lly provide adequate protection in a mild, low-impingement angle envir onment, but they fare poorly in a harsh, high-impingement angle enviro nment. This paper describes a new multilayer tungsten carbide-based co ating, which has been developed to protect components both in low and high impingement angle environments. The multilayer coating is deposit ed by the chemical vapor deposition technique and consists of an outer tungsten carbide layer with a fine-grained, layered morphology at the top of a columnar tungsten inner layer. It can be deposited on severa l metals and alloys used by the aerospace industry at low temperatures without degrading their mechanical properties. The erosive wear behav ior of the multilayer coating is compared with titanium nitride coatin gs deposited by the physical vapor deposition technique.