Friction improvement of new generations of engines by PTWA cylinder bore coating and new piston rings

摘要

In an effort to inhibit a climate change, the European Union has decided to reduce the CO_2 emissions by approx. 30% by year 2020, as compared to the level of emissions in year 1990's [1]. In general, traffic is responsible for 20% of all CO_2 emissions and 84% of those emissions result specifically from road traffic [2]. In accordance with the present targets of the CO_2 emission reduction the automotive industry has to meet strict regulations. The strict emission goals can only be reached by weight reduction of the vehicle and by an improved efficiency of engine and drive train. Close to 50% of the friction losses in a combustion engine result from the interaction between the piston ring and the cylinder bore surface [3]. Therefore the cylinder bores as well as the piston rings were coated with new, low-friction materials. The friction behaviour was characterized in linear reciprocating tribometer-Test in order to identify the best combination of bore and ring coatings.