*Mark A. Pellman¹, Wolfgang Fukarek², Steffen Hoppe³, Troy Kantola^4
1Tenneco, VTD Vakuumtechnik Dresden GmbH, Fort Collins, CO; ²Tenneco, VTD Vakuumtechnik Dresden GmbH, Dresden, Germany; ³Tenneco, Powertrain, Burscheid, Germany; ⁴Tenneco, Powertrain, Plymouth, MI
Tetrahedral Amorphous Carbon (Ta-C) coatings, first developed in the 1990s, so far have found only limited commercial success due to high intrinsic stress and limited scalability of cathodic arc and HIPIMS processes. Recently, VTD (Vakuumtechnik Dresden GmbH), a Unit of Tenneco, successfully scaled up the laser arc deposition process, originally developed at Fraunhofer Institute for Material and Beam Technology IWS (Dresden, Germany), for the coating of piston rings. In parallel, the DREVA 1050 coating system was redesigned for higher capacity and lower Cost of Ownership. This paper will highlight the development of Tenneco’s new generation tetrahedral amorphous carbon (ta-C) piston ring coating, which is setting new standards in high-performance, low-friction piston ring technology. Compared to any ring coatings, Ta-C-coated piston rings show outstanding durability, friction, and scuff resistance and contribute, in combination with advanced top and oil ring designs, to fuel economy savings up to 1.2 percent for commercial vehicle engines. This paper demonstrates how Ta-C provides superior wear and scuff resistance.