The evolution of piston rings has necessarily been in the direction of increased sealing against the cylinder wall, accompanied by decreased friction, which means increased sliding properties and reduced scuffing. Trends in engine design have increased demands placed on piston rings, such factors as increased heat, increased pressures, reduced oil viscosity, environmental concerns and regulations, and generally much harsher conditions inside the cylinder overall.
Piston rings have over time been improved by chromium plating, and then in 1995, Federal-Mogul improved piston ring performance still further with their CKS technology, which embedded nanoparticles of aluminum oxide in microscopic cracks in the chromium surface coating. This allowed Federal-Mogul to become market leader in piston rings worldwide.
Anticipated market pressures and demands on the performance of piston rings, particularly in Diesel applications, led Federal-Mogul to tackle, in 2003, a hypothetical solution that was "known" in the industry to be impossible. This was to embed diamond nanoparticles in the chrome surface plating through electro-mechanical dispersion. They were nevertheless able to get to volume production of rings with chromium coating, embedding nano-diamonds in microscopic cracks of a layered chromium coating.
Engines using diamond coated rings are expected to exhibit a 50 to 70% increase in durability, while engine temperatures were simultaneously being raised by 30-80o C., pressure increased to 200 bar, oil consumption reduced by 30%, and blow-by by 20-30%.
Adoption of the GDC diamond coated rings has included DaimlerChrysler, Volvo, MAN, DAF, and IVECO in Heavy Duty Diesel markets, and DaimlerChrysler, Volkswagen, and BMW in Light Diesel Vehicle engine applications.