Ceramic Coated Piston Rings for Internal Combustion Engines

This paper reports the development and formulation of a new cost effective means of applying ceramic tribology coatings to sealing rings. This coating, though developed with the support of the U.S. Army Tank Automotive and Armaments Command for use on Low Heat Rejection (LHR) high output diesel engines, can be used on any internal engine compression seal ring. It is not limited for use in LHR diesel engines. Applying ceramic coating, especially on the compression piston ring, reduces the friction losses and wear of sliding contact surfaces. This will result in increased engine efficiency and durability. The work presented examines both laboratory and small bore engine testing of this technology. Laboratory tribometer tests compare the ceramic coating to existing and experimental piston ring tribosurfaces. Friction and wear performance demonstrated in the laboratory is verified for use in LHR diesel engine application. Low raw material cost coupled with ease of application and high deposit efficiency of the ceramic make this coating a viable candidate for commercialization.