Nano-Coating Replaces Cylinder Liners for Advanced Engines

Ford Research Centre Aachen (Germany) is developing a thermally sprayed nano-coating using a Plasma Transferred Wire Arc (PTWA) process that could replace the heavier cast iron liners that provide the necessary wear resistance of cylinder bores in aluminum block engines.
The thin, wear-resistant coating reduces weight and improves friction performance while delivering equal durability and reliability. Fuel consumption can be reduced by utilizing lightweight construction as well as by decreasing internal friction losses in the drive train.
Modern engine blocks are partly made of cast iron or aluminum material whereas for the later hypo-eutectic AlSi-alloys dominate. Due to the low hardness, surfaces made of these alloys cannot be used as a friction partner for the piston rings. Cast iron liners are often inserted into the engine block to provide a wear-resistant surface for the piston rings. This work describes how cast iron liners can be replaced by thin, nanocrystalline iron based coatings in order to decrease friction losses as well as reduce the engine weight. http://www.greencarcongress.com/2008/04/ford-developing.html#more