Federal-Mogul Corporation has developed a new piston ring coating that supports vehicle manufacturers’ efforts to make petrol engines more fuel-efficient.

The patented ‘CarboGlide’ coating delivers a claimed direct improvement in fuel economy and CO2 emissions by reducing ring friction by up to 20% as compared to nitride or other commonly used coatings. Its high wear resistance will withstand an engine’s full operational life – even in the latest generation of high-output petrol engines with turbocharging or direct injection. CarboGlide additionally protects the cylinder surface from scuffing and scoring, especially under the most critical lubrication conditions, because of its high chemical and physical stability, the supplier said.

The superior coating properties are achieved due to a multi-layer microstructure and a special coating composition that contains carbon, deposited in diamond-like form, as well as hydrogen and tungsten. The unique structure can be produced for a coating thickness of 10 microns, more than three times that of the industry’s latest DLC coating. A specialised advanced process based on the combination of physical vapour deposition and plasma-assisted chemical vapour deposition, specifically developed for piston ring application, is used in applying CarboGlide. The coating’s multi-layer architecture, together with the company’s surface machining and finishing expertise, ensure the integrity of the coating structure, optimal adhesion of the coating and high coating stability on both steel and cast iron rings.

CarboGlide is Federal-Mogul’s third and most advanced generation of the company’s DLC coated ring technology. The coating was developed in Burscheid, Germany. 

Several vehicle manufacturers will launch engines using CarboGlide-coated piston rings beginning this year.